Marmara University School of Medicine

Year 2

2009 - 2010

Pathology Laboratory Guide

CONTENTS

1- Cell and tissue injury course I; Assist. Professor Süheyla Uyar Bozkurt

2- Cell and tissue injury course II; Assoc. Professor Rengin Ahıskalı

3- Hematopoeietic System and Related Didorders Course; Assist. Professor Süheyla Uyar Bozkurt

4- Musculoskelaetal, Integumentary Systems and Realted Disorders: Assoc. Professor Funda Eren

5- Respiratory System and Related Disorders Course: Assist. Professor Süheyla Uyar Bozkurt

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INTRODUCTION TO MICROSCOPIC EXERCISES

A considerable time of the Pathology Course is devoted to microscopic analysis of tissues. This is not because we wish you all to become pathologists, but we believe that understanding the cellular and structural changes in the tissues is essential for you to understand the biological nature and the clinical expression of human diseases. Thus, the laboratory material must be approached with this perpective.

Much of what you'll acquire in the way of histopathologic information will be self-taught. You will utilize the microscope and the slide sets loaned to you for each laboratory session. In the beginning of the year, a text syllabus will be supplied, by the Department of Pathology. The laboratory sessions are intended to assist you in your efforts to learn pathologic anatomy. The design of these sessions assumes a significant effort on your part, before coming to class.

Coming to class without a reasonable study will ensure that your time in class will be wasted. Ordinarily, if you've been staring at a given slide for 10-15 minutes to figure it out, without any success, additional time spent will not be rewarded. Any additional time you could spare would better be spent after discussion in lab, reviewing what you been stumped by.

Experience has shown that a systematic approach to each slide works the best.

1. Familiarize yourself with the text and lecture material relevant to the condition under consideration before studying the slide.

2. Inspect the slide carefully with the naked eye before putting it under magnification. This will often enable you to spot the one focal area which is abnormal, an area which might be missed under the microscope with its narrow field.

3. If you have not been told, begin the microscopic exercise by deciding what tissue is represented on the slide (Is it a pancreas, brain, etc?). If you have been told, review the features which would allow you to identify it. In either event, you should next look up to the image of the tissue in your histology textbooks. It aids you in recognizing the normal composition of the tissue you are examining.

4.Then, and only then, continue the exercise by examining the section for deviations from that of normal.

a. Be systematic. Devise a personal system which ensures that you will cast an eye over every bit of the section. Get into the habit for instance of sweeping back and forth from top to bottom or up and down from left to right of the section covering it completely.

b. Start with the lowest available magnification which provides the widest field. When you recognize any abnormality under the lowest power, go after it at higher magnification in order to figure it out,for instance, what kind of cells make up that purple blotch. When you have figured it out, go back to the lowest magnification to see it again. Before long, you'll be telling polys from plasma cells with the low power scanning lens. As you get comfortable with the low power, you'll be able to diagnose things by pattern recognization (which is how you now recognize your friend's face in a crowd).

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c. Avoid to give any diagnosis, since it's often wrong for beginners. Instead describe the abnormal elements to yourself one by one. For example vessels in left field, fibroblasts in center field, and atypical pleomorphic cells in right field. Then, try to put the elements together into a diagnosis. It works.

d. Before long, you'll be able to generate a differential diagnostic list appropriate to various situations. It is just a matter of matching up the described elements with this list.

5. As questions appear in the syllabus, answer them carefully. They are desingned to be helpful and freguently will give you insight into important clinical considerations.

PATHOLOGY LABORATORY EXAMINATION:

Pathology practical examnation will be held in the multidisiplinary laboratory. This exam contains multiple choice, open ended or an assay questions from slide presentation.

The score of each pathology labaratory examination changes. It is decided by chairman of subject course in each course.

Students who do not fulfill the minimal required attendance limits, are not eligibal to participate in the pathology practical exam.

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CELL AND TISSUE INJURY COURSE I

SYSTEMATIC APPROACH FOR THE EXAMINATION OFMACROSCOPIC SPECIMENS

• IMPORTANT NOTE : In order to understand the pathologic findings, you have to know the normal anatomic structure of the organs and tissues.• In order to uderstand the underlying mechanism off these pathologic findings, you have (to know the pathopysiological mechanisms of these pathologic processes that are going to be examined.• When examining the gross specimens, (try to answer the following questions? Is there any change in the size of the organ ?

If there is, is it diffuse or focal? Is there any change in the color of the organ ?

If there is, is it diffuse or focal? Is there any change in the consistency of the; organ ?

If there is, is it diffuse or focal? Is there any tissue defect in the organ ?

If there is, is it superficial, intraparemchymal, or subepithelial

CHANGES IN THE SIZE, CONSISTENCY, COLOR, AND COMPOSITION OF ORGAN'S

CHANGES IN THE SIZE OF ORGANS

Increase in the Size of the Organ

Diffuse — > Increase in Cellular Content

( Increase in either cellular content or size of the cells)

Local Cells of the Organ

*hypertrophy HYPERTROPHY - HEART*hyperplasiaHYPERPLASIA - PROSTATE NODULAR HYPERPLASIA - THYROID * neoplasiaLYMPHOMA - SPLEEN ( Normal Spleen)

Non-local cells

*inflammatory cells

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MILIARY TUBERCULOSIS - LUNG GRANULOMATOUS INFLAMMATION TESTIS ACUTE REJECTION – KIDNEY*neoplastic cells (invasion / metastasis) LINITIS PLASTICA STOMACH

Increase in Luminal content

*dilatationHYPERTROPHY -URINARY BLADDERHIDROPS – GALLBLADDER

Increase in Ground Substance

*mucin, fibrin, pigments, etc,FATTY CHANGE -- LIVERANTHRACOSIS - LUNGATHEROSCLEROSIS - CHOLESTEROL ACCUMULATION FATTY CHANGE - HEART AMILOIDOSIS - KIDNEY

Increase in Blood Volume

*Increase in Blood In flow-Hypererma* Impaired Blood Outflow-CongestionNUTMEG LIVER (systemic) TORSION - TESTIS (Local) MENINGEAL CONGESTION

Focal*Inflammatory*Blood Accumulation*Neoplastic

Decrease inSize

Diffuse*atrophy RENAL ATROPHY ----> flbrosis*hypoplasiaRENAL HYPOPLASIA

Local*local atrophy*scar formationCHRONIC PYELONEPHRITIS

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CHANGES IN THE CONSISTENCY OF ORGANS

Softening *destruction of the architecture of an organ (necrosis)INFARCTION - SPLEENINFARCTION - MYOCARDIUMTRANSMURAL INFARCTION - SMALL BOWEL*decrease in ground substance *edema, serous fluid accumulation NASAL POLYP HEMATOMA – SPLEEN

Hardening

* increase in ground substance CIRRHOSIS – LIVER*infiltration by inflammatory cells / neoplaistic cellsBRONCHOPNEUMONIA - LUNGCHONIC CHOLESISTITIS - GALLBLADDERFIBROMA - OVARY*abnormal, accumulations (calcification, amyloidosis) AMYLOIDOSIS - KIDNEY CALCIFICATION -• PLACENTA.

Crispyness

*necrosisTUBERCULOSIS - APEX OF THE LUNGCOAGULATION NECROSIS - KIDNEY - RENAL, CELL CARCINOMA*decrease in substances giving elasticity to organs (osteogenesis imperfecta,osteoporosisDEGENERATIVE ARTRITIS

CHANGES IN THE COLOR AND COMPOSITION OF ORGANS

Darkening

*increase in blood flowMENINGEAL CONGESTIONCHRONIC PASSIVE CONGESTION - LUNGCHRONIC PASSIVE CONGESTION - LIVER (NUTMEG LTVER)TORSION - TESTISINFARCTION - SMALL INTESTINEHEMATOMA.- SPLEEN*deposition of lipofuscin* increase in melanin pigment*increase in pigment ANTRACOSIS – LUNG

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Paleness *decrease in blood flow INFARCTION SPLEEN INFARCTION MYOCARDIUM INFARCTION PLACENTAACUTE REJECTION - KIDNEY*decrease in melanin pigment*scar tissue formation CHRONIC PYELONEPHRITIS

Discoloration *accumulation of pigments ANTRACOSIS - LUNG* accumulation of lipid FATTY CHANGE - LIVER NUTMEG LIVERATHEROSCLEROSIS - CHOLESTEROL ACCUMULATION FATTY CHANGE - HEART AMILOIDOSIS - KIDNEY CHOLESTEROLOSIS - GALL BLADDER

MACROSCOPIC EXAMINATION OF THE SPECIMENS

HD-l . HYPERTROPHYORGAN: HeartGross Findings: This transverse slice from the heart displays prominent difference between the diameters of ventricle walls. Notice a white area of flbrosis in one of the walls.Descriptive Notes: Hypertrophies heart may achieve weights of 700 to 800 gr instead of 350gr.Normally the thickness of the wall of the right ventricle is 3 to 5 mm and that of the leftventricle 1.3 to 1.5 cm. Greater weight or ventricular thickness indicates hypertrophy.

HD-2: HYPERPLASIA ORGAN: ProstateGross Findings: Two prostatic lobes are seen. They are enlarged, firm and nodular. The cut surfaces are also nodular and contains some minute cysts. The size of nodules vary from 0.5 to 1.5cm.Descriptive Notes: This increase in size is in response to hormonal changes that occurs with the aging process.

HD-3: HYPERPLASIAORGAN: Thyroid (Nodular Hyperplasia)Gross Findings: Thyroidectomy specimen with glistening, jelatinous, nodular surfaces is seen. At cut section you can discriminate fibrous bands causing nodular structures.

Descriptive Notes: In the adult, the normal thyroid gland weighs 20 to 25 gm. The most common cause of the nodular hyperplasia is the of lack of iodine in the diet resulting insufficient production of throid hormones. This cause increase the sythesis and release of TSH (thyroid stimulating hormone), resulting in enlargement of the thyroid.

HD-4: LYMPHOMAORGAN: SpleenGross Findings: In the cut section of the spleen, you see numerous nodular masses(approximately 0.6-0.8 cm. in dimension). This leads to diffuse enlargement of the spleen.7

Descriptive notes: These nodular masses are formed by neoplastic proliferation of lymphocytes which are actually local cells of the spleen.

HD-5: MILLIARY TUBERCULOSISORGAN: LungGross Findings: There are multiple small (pin-point to a few millimeters), yellow whitedistinct foci. This leads to diffuse enlargement of the lungs.Descriptive notes: These foci are formed by granulomatous inflammation.

HD-7: ACUTE REJECTIONORGAN: KidneyGross Findings: The kidney is larger, harder, and paler than normal.Descriptive Notes: Enlargement of the kidney caused by edema, and diffuse mononuclear cell infiltration. Result of humoral rejection extensive renal parenchymal necrosis seen.

HD-8: LINlTlS PLASTICAORGAN: StomachGross Findings: There is diffuse thickening of the gastric wall which has given rise to a term “leather-bottle” stomach also called linitis plastica.Descriptive Notes:Tumour cell infiltration to the gastric wall ends up with diffuse thickening of the gastric wall.

HD-9: HYPERTROPHY – DILATATIONORGAN: Urinary Bladder Gross Findings: This is a partial cystectomy spesimen. The bladder is turned inside out so that you can see the pale mucosa. The cavity of the urinary bladder is enlarged. The bladder wall is thicker than normal.Descriptive Notes: Vesical obstuction caused dilatation of the baladder and hypertrophy of the muscle layer. Hypertrophy of the muscle bundles produce trabeculation.

HD-11: FATTY CHANGEORGAN: LiverGross Findings: A slice of the liver is seen. Liver is enlarged, yellow, smooth, firmer than normal and greasy. The capsule remains smooth and glistening.The lumina seen on the cut surface are the branches of the portal vein.Descriptive Notes: the normal adult liver weighs 1400 to 1600 gms. Fatty change results from defective oxidation of fatty acids and aberrant mitochondrial function.

HD-12: ANTHROCOSISORGAN: LungGross Findings: Accumulation of this pigment blacken the tisues of the lung.Descriptive Notes: The most common exogeneous pigment is carbon or coal dust, which is a virtually ubiquitous air pollutant of urban life.

HD-13: ATHEROSCLEROSIS-CHOLESTEROL ACCUMULATIONORGAN: Vessel WallGross Findings: You see an opened vessel wall. On the inner surface there are elevated areas of different diameter in size, yellow-white in colour and with irregular lipid plaques.Some plaques are calcified, these can be recognised with their white color and rigid appearance. The size of the atheromatous plaques are varible and some show coalescence.Descriptive Notes: Endothelial cell damage and increased total cholesterol and

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decreased HDL cholesterol cause atherosclerotic plaq formation.

HD-14: FATTY CHANGEORGAN: HeartGross Findings: The heart is enlarged and softened. It is yellow in colour. You can also see atherosclerotic yellow lipid plaques in the opened vessels.

HD-15: AMYLOIDOSlSORGAN: KidneyGross Findings; Kidney is enlarged , firm and have a waxy appearance.Descriptive Notes: Extracellular hyaline amorphous material is accumulated in glomeruli and vessel wall. Painting the cut surface with iodine imparts a yellow colour is transformed to blue violet.

HD-16: PASSIVE CONGESTIONORGAN: OvaryGross Findings : The organ is diffusely enlarged, firm, and cyanotic. Descriptive Notes: This is due to twisting of ovary that cause obstruction of venous return resulting in intense congestion. Ovarian torsion is uncommon.

HD-17: CHRONIC PASSIVE CONGESTIONORGAN: Liver NUTMEG LIVER (normal adult liver weight is 1400-1600gm.) Gross Findings: There is dusky red cyanosis and diffuse increase in liver size and weight. On the cut surface the central congested areas appear darker than the pale peripheral portions of the lobules and thus compose the so-called nutmeg pattern.Descriptive Notes: Passive congestion of the liver results from right-sided heart failure or obstruction of the inferior vena cava or hepatic vein. When you think about the normal circulation of the liver you will easily understand why the central areas are primarily affected. We see hemorrhagic necrosis in the pericentral zones. Whereas the peripheral hepatocytes, suffering from less hypoxia, develop fatty change. This zonal difference gives red [centre of the lobule] and yellow (periphery-of the lobule) discoloration so-called "nutmeg" liver to the organ.

HD-18: PASSIVE CONGESTIONORGAN: Testis (Torsion)Gross Findings: Testis shows slight but diffuse enlargement The organ is tense andcyanotic.Descriptive Notes: There is an impairment of venous return from the testis due to the twisting of the spermatic cord resulting compression of testicle veins.

HD-19: CONGESTIONORGAN: Brain —> Meningeal CongestionGross Findings: The blood vessels of the meninges are engorged with dark red blood. There is also diffuse increase in the size and weight of the organ due to secondary edema formation.

HD-20: ABSCESSORGAN: Spleen .Gross Findings: Spleen is enlarged. Acute inflammatory cell infiltration results with a tissue defect that you can notice on the cut section of the spleen.Descriptive Notes: Normally in the addult spleen weighs, about 150 gm and measures 12 cm in lenght, 7 cm in width, and 3 cm in thickness.

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HD-21: TUBERCULOSISORGAN: Apex of the LungGross Findings: At the apex of the lung there is an intraparanchymal tissue defect. At the centre of the defect with a close inspection one can easily identify the necrosis.Descriptive Notes: Mycobacterium cause tuberculosis.The type of the necrosis is called caseification necrosis.

HD-22: ATROPHYORGAN: KidneyGross Findings: The cut section of the kidney reveals dilatation and deformation of the calyces, irregular loss of renal parenchyma with scarring. Its surface is granular with depressed scars. Descriptive Notes: Atrophy is due to progressive destruction and loss of renal parenchyma.

HD-23: HYPOPLASIA(congenital)ORGAN: KIDNEYGross Findings:The size of the kidney is diffusely decreased. Its surface is smooth and normal in appearance. The number of renal lobes and pyramids is 6 or fewer (normal kidney has about 12 pyramids).

HD-24: CHRONIC PYELONEPHRITISORGAN: KIDNEYGross Findings:The cortical surface of the kidney contains irregular, broad depressed area (scar formation) of cortical fibrosis and atrophy leading to focal decrease in size of the organ. On cut section you see dilatation of calyces with atrophy, calculi and scarring of the overlying cortex. The fibrotic area is paler than surrounding tissue.Descriptive Notes: Chronic pyelonephritis is caused by recurrent and persistent bacterial infection secondary to urinary tract obstruction, urine reflux, or both. In chronic pyelonephritis recurrent acute and chronic inflammation leads to progressive atrophy, fibrosis and scarring.

HD-25: INFARCTIONORGAN: SPLEENGross Findings: On the cut section of the spleen you see multiple, pale, wedge shaped, well deliniated infarcts beneath the capsule. The infarcts which are wedge shaped have their apex pointing toward the focus of vascular occlusion. Since all the dependent tissue out to the periphery of the organ is affected, the external aspect of the organ forms the base of the wedge.Descriptive Notes:This is an example of white infarct which is seen secondary to the arterial occlusion of the solid organs.

HD-26: INFARCTIONORGAN: PlacentaGross Findings: On cut section of the placenta reveals a white-tan and firm area of necrosis. It is also wedge shaped with apex at the maternal surface.Descriptive Notes: This is also an example of white infarct. It results from cessation of blood supply to intervillous space and necrosis of villi .

HD-27: TRANSMURAL INFARCTORGAN: Small bowelGross Findings: A segment of small bowel is seen. A large part of this segment is 10

intensly congested and dark purple. This discoloration fades gradually into the adjacent segments of the normal bowel, that is the demarcation is not sharply defined.Descriptive Notes: This is also an example of a red infarct. We see red infarct both in arterial and venous occlusions of the small bowel due to the fact that it has rich in arterial anastomoses.

HD-29: CIRRHOSISORGAN: LiverGross Findings: The liver is harder than normal due to fibrosis. Its surface shows diffuse nodularity that reflects nodular regeneration and scarring.Descriptive Notes: Cirrhosis of the liver is the terminal sequel of repeated injury to the liver parenchyma. The result is the formation of broad fibrous bands separating regenerative nodules that do not have the normal achitecture of liver lobules.

HD-30: BRONCHOPNEUMONIAORGAN: LungGross Findings: The lung shows patchy distributed firm and gray-red to yellow colour, elevated nodular airless areas due to inflammatory infiltration.These nodules are distributed along with the bronchioles so called bronchopneuonia.Descriptive Notes: It results from aspiration of organisms causing inflammation and necrosis of underlying parenchyma

HD-31: CHOLESTEROLOSISORGAN: Gall bladderGross Findings: Its mucosal surface shows minute yellow patches due to cholesterolaccumulation . This is called as a "strawberry gallbladder".Descriptive Notes: It is results from abnormal deposition of mixtures of cholesterol and triglyceride in macrophages in the lamina propria of the gallbladder.

HD-32: FIBROMAORGAN: OvaryGross Findings: The tissue is harder and bigger than a normal ovary because of infiltration by neoplastic cells arising in the ovarian strorna. The ovary appears as a white firm, mass composed of interlacing bundles of fibers.Descriptive Notes:It is a benign neoplasm of the ovary.

MICROSCOPIC EXAMINATION OF THE SLIDES

SLIDES YOU ARE GOING TO EXAMINE IN EACH LABORATORY SESSION CELL RESPONSE TO INJURY AND ADAPTIVE CELL REACTIONHEMODYNAMIC DISORDERS AND ABNORMAL ACCUMULATIONS MORPHOLOGY OF ACUTE AND CHRONIC INFLAMMATION

CELL RESPONSE TO INJURY AND ADAPTIVE CELL REACTION

N- 18 FATTY CHANGEOrgan: LiverPATHOLOGICAL FINDINGSGross findings: HD-15Microscopic findings: This H&E stained slide is prepared from a grossly yellow

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colored enlarged liver. The parenchymal cells (hepatocytes) show marked fatty change. Note the variable sized lipid vacuoles in the cytoplasm and peripherally displaced nuclei. Remember that fat globules appear as empty spaces with routine H&E stain.

A-1 COAGULATION NECROSISOrgan: PlacentaPATHOLOGICAL FINDINGSGross findings: HD-26Microscopic findings: The section is prepared from placenta. One part of the section has undergone coagulation necrosis. These areas are acidophilic. The cells have “tombstone” appearence that is nuclear detail is lost, only the basic cellular shape, the silhouette of the villi and cells are preserved. You can still recognise the cell outline and tissue architecture.

A-3 FAT NECROSISOrgan: Breast – fat tissuePATHOLOGICAL FINDINGSMicroscopic findings: The section is from an ill-defined mass in the breast present for 3 weeks. This section consists largely of fibrous tissue with scattered lymphocytes. Nearby there are islands of fat tissue which is replaced by histiocytes in some areas. Note that you can see the shadowy outlines of necrotic fat cells and they do not have nuclei.

B-8 CASEIFICATION NECROSISOrgan: LungPATHOLOGICAL FINDINGSGross findings: HD-21 Microscopic findings: In this section of the lung, there are several round, nodular structures which are called granulomas. Each granuloma consist of epithelioid histiocytes (macrophages) in the middle, surrounded by lymphocytes. You may see langhans type giant cells in some of them. This type of giant cells, nuclei arranged peripherally. In the center of a few of the granulomas, necrosis is seen. This is a special type of necrosis called caseification necrosis. The outlines of the cells are not preserved. Instead you see amorphous eosinophilic (pink) material which contains cellular debris.

A-13 METAPLASIAOrgan: Cervix PATHOLOGICAL FINDINGSMicroscopic findings: The section is prepared from uterine cervix. On one side there is squamous, on the other side columnar epithelium is seen. You may easily see the squamocolumnar junction where squamous epithelium changes to columnar epithelium.called squamous metaplasia. There are glands in the endocervical portion of the section, lined by similar columnar epithelium. When you look at the surface epithelium closely you will see that some parts of the columnar epithelium transform to squamous type of epithelium.

A-13B METAPLASIAOrgan: StomachPATHOLOGICAL FINDINGS

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Microscopic findings: The section is from a gastrectomy specimen. On the slides you will see the gastric mucosa lined by columnar epithelial cells. At some parts the gastric epithelium is replaced by intestinal metaplasia which is composed of goblet cells, absoptive ‘brush border’ cells. On the other slide stained with PAS-Alcian Blue 2,5 normal gastric epithelium is bright pink (neutral mucin) and the intestinal metaplasia areas are purple (acidic mucin) in color. There are goblet cells in these metaplastic areas.Mark the difference.

P-22 HYPERPLASIAOrgan: ProstatePATHOLOGICAL FINDINGSGross findings: HD-2Microscopic findings: Examine both stromal and epithelial components. The fibromuscular stroma and glands are proliferated. The glandular epithelium is generally hyperplastic, some glands show cystic dilatation and contain corpora amylacea in the lumina.

A-14 ATROPHY-NODULAR HYPERPLASIAOrgan: Thyroid PATHOLOGICAL FINDINGSGross findings: HD-3Microscopic findings: You see one of the nodules which has various sized follicles. These follicles have colloid in their lumen and their epithelial lining is cuboidal. Around some follicles a homogenous pink area of hyalinisation is noted. Surrounding the nodule fibrous tissue and atrophic thyroid follicules and granulomatous inflammation are seen. Atrophic follicles which are compressed are small and their epithelial lining is flattened.

HEMODYNAMIC DISORDERS AND ABNORMAL ACCUMULATIONS

A-15 ANTHRACOSISOrgan: Lymph nodeHistology of the organ: A lymphoid stroma which contains lymphoid follicles some of which have germinal center. The node is surrounded by a fibrous capsule beneath which are found lymphatic sinuses.

CASEClinical history: A 78 year-old man underwent lobectomy and lymph node dissection with diagnosis of lung cancer.

PATHOLOGICAL FINDINGSGross findings: HD-12(Antracosis in lung)Microscopic findings: In the center of the lymph node lymphoid tissue is replaced by a fibrotic stroma rich in blood vessels. This stroma is infiltrated by histiocytes which contain black granules (carbon pigment). You may also see carbon pigment within the extracellular space.

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A-7a HEMOSIDEROSISOrgan: OvaryHistology of the organ: A stroma composed of theca cells contains follicules lined by granulosa cells, corpora lutea by luteinized theca cells.

CASEClinical history: A 30 year-old woman underwent partial oopherectomy due to an ovarian mass.

PATHOLOGICAL FINDINGSMicroscopic findings: The slide is prepared from an ovary which has a focus of endometriosis. Here we see an area of old bleeding. This area is mainly composed of numerous hemosiderin-laden histiocytes. Try to identify intracytoplasmic bright yellow-brown appearing tiny granules of hemosiderin within histiocytes. These cells are called “siderophages”.

N-17 MELANIN PIGMENTOrgan: SkinHistology of the organ: A dermis containing hair follicles and sweat glands is covered with a hyperkeratotic epidermis.

CASEClinical history: A 45 year-old woman underwent excisional biopsy for a pigmented cutaneus lesion found in the dorsum of the wrist.

PATHOLOGICAL FINDINGSMicroscopic findings: A lesion composed of melanin containing melanocytes is seen within the dermis. The lesion also contains some cells which don’t contain melanin. These cells have plump nuclei.

C-3a CONGESTIONOrgan: SpleenHistology of the organ: A red pulp composed of red blood cells and white pulp composed of lymphoid tissue is observed. The white pulp contains some lymphoid follicles some of which have germinal centers. The organ is surrounded by a fibrous capsule. Fibrous trabeculae extend from the capsule into the stroma. The red cells of the red pulp pare within vascular structures called the splenic sinuses.

CASEClinical history: A 19 year-old man underwent splenectomy for rupture of spleen after a road accident.

PATHOLOGICAL FINDINGSMicroscopic findings: The splenic sinuses are dilated and filled with red blood cells.

C-6e INFARCTIONOrgan: Small intestine

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Histology of the organ: The gut wall consists of a mucous membrane, muscular coat and a serous membrane. The mucous membrane has a lamina propria lined by surface epithelium which exhibits villi. In the lamina propria glands are found.

CASEClinical history: A young man who had appendectomy 6 months ago presented with symptoms of ileus. At operation intestinal adhesions and a strangulated segment of ileum was found.

PATHOLOGICAL FINDINGSGross findings: HD-27Microscopic findings: An intense congestion and silhouettes of intestinal villi are seen. In some slides there is extensive red blood cell extravasation and necrosis of the bowel.

C-4A, 4B THROMBOSISOrgan: A: Artery, B: VeinHistology of the organ: The artery is composed of an intima, muscular coat and an adventitial fibrous tissue. In the vein these layers are not as prominent as in the artery.

CASEClinical history: The leg of a 70 year-old woman has been amputaded due to vascular occlusion.

PATHOLOGICAL FINDINGSMicroscopic findings: A: This slide illustrates artery occluded by thrombi. This is an organized thrombus.The wall of the arteries is calcified. B: In this section we see an enlarged vein in which the lumen is completely obliterated by an organized thrombus.

B-6 ABSCESSOrgan: SkinHistology of the organ: A dermis containing cutaneous appenages such as hair follicles, sebaceous glands and sweat glands lined by an epidermis composed of stratified squamous epithelium. Beneath the dermis begins the subcutaneous adipose tissue.

CASEClinical findings: A 20 year-old young male underwent excision of a cutaneous abscess wall.

PATHOLOGICAL FINDINGSMicroscopic findings: There is a area of liquefaction necrosis filled with neutrophils intermingled with histiocytes and giant cells. The wall of the necrotic area is rich in blood vessels.

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M-36a ACUTE INFLAMMATIONOrgan :AppendixHistology of the organ: The wall of the appendix is composed of a mucous layer rich in lymphoid follicles with prominent germinal centers, a muscular coat and a serous membrane.

CASEClinical findings: A 30 year-old female with severe abdominal pain underwent appendectomy with a diagnosis of acute appendicitis.

PATHOLOGICAL FINDINGSMicroscopic findings: In this slide you see an inflamed appendix wall. Try to examine each layer subsequently. There is a purulent exudate in the lumen. The continuity of the mucous membrane is not maintained because of the erosion seen just beneath that exudate. Note that the edematous wall is diffusely infiltrated by neutrophils.

M-10 PEPTIC ULCEROrgan: StomachHistology of the organ: The wall of the stomach is composed of a mucous membrane lined by a secretory epithelium, a muscular coat and a serous membrane. Gastric glands are found within the lamina propria of the mucous membrane.

CASE:Clinical findings:A 50 year-old man underwent partial gastrectomy due to a chronic peptic ulcer.

PATHOLOGICAL FINDINGSMicroscopic findings: On both sides of the slide you can see normal gastric tissue and in the middle there is a local tissue defect. Here, epithelium is the ulcerated. The surface of it contains an inflammatory exudate composed of necrotic tissue debris and neutrophils. Beneath this try to see the granulation tissue which is surrounded by a thin layer of fibrous collagenous tissue.

M-11 FOREIGN BODY REACTIONOrgan: SkinHistology of the organ: A dermis containing cutaneous appendages such as hair follicles, sebaceous glands and sweat glands lined by an epidermis composed of stratified squamous epithelium. Beneath the dermis begins the subcutaneous adipose tissue.CASE:Clinical findings:A 50 year-old man has 1cm. diameter firm, mass lesion on his face. Physical examination revealed cystic mass.The excisional biopsy was performed.

PATHOLOGICAL FINDINGSMicroscopic findings: In this section there is ruptured follicle cyst is seen. Around cyst there is a foreign body granulation tissue composed of giant cells and lymphocytes. Such foreign body giant cells have nuclei scattered haphazardly about the cell. There is refractile hair shaft fragments in some of these giant cells.Remember the difference between foreign body giant

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cells and Langhan’s type giant cells that seen in Tuberculosis infection.

CELL AND TISSUE INJURY COURSE II

PATHOLOGY of MASS LESIONS and TISSUE DEFECTS LABORATORY

Tissue defectsSuperficial (On the surface)ErosionUlcer

Tissue defectsWithin the solid tissue:AbscessCystic change (due to old hemhorrage, necrosis, etc.) – pseudocyst True cyst: non neoplastic (congenital or acquired)Cystic neoplasmParasitic cyst

Mass lesionsGrowing on the surface/ into the lumen of viscera:Polyp – polypoid growth (sessile or pedunculated)Papilloma – papillary growthVerrucous / fungating / exophytic / vegetating growth

Mass lesionsWithin the solid tissue (local growth):encapsulated / unencapsulated (well demarcated or invasive border)

Features to be taken into consideration when examining a mass lesion: Localization and extent within the organ (or depth of invasion for hollow viscera) Size Number: Single - multiple Growth pattern: polypoid, ulcero-infiltrative, nodular, etc. Consistency (usually harder than surrounding normal tissue) soft – rubbery

(elastic) – hard (more fibrous tissue) – stone hard (calcified) Border: encapsulated - well demarcated but unencapsulated - invasive with

irregular border Cut surface: Homogenous – heterogenous

solid, nodular - predominantly cystic - predominantly solid with small cystic areas

fibrillary, myxoid / gelatinous, ......- like (cartilage –like / cartilaginous)

color (predominantly ): white - yellow (lipid content) - various colors (variegated) - unremarkable (not different from surrounding organ) - other (specify)

Other features : the presence of prominent areas of: fibrosis / fibrous scars - necrosis – hemorrhage

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MACROSCOPY

M1 - RENAL TUBERCULOSIS The kidney is slightly enlarged with irregular nodular cortex. The cut surface shows multiple round yellowish to grey-white cavitary areas lined with soft friable material (caseous necrosis) and walled off by white, solid fibrous tissue in the parenchyma. You can see this material also filling the pelvis and calyces. Calyces and renal pelvis are dilated.

M2 - SPERMATOCELEYou see a cystic mass with a thickened, fibrotic wall and a small compressed testis in one pole. The internal surface is irregular, matte(dull) and yellowish to brownish color due to accumulated cellular debris.

M3 - CHRONIC NON - SPESIFIC CERVICITIS WITH NABOTHIAN CYSTSIn this hysterectomy specimen, the cervix is studded with mucus containing cysts. These are the result of obstruction of the openings of endocervical crypts, accumulated secretion gives rise to retention cysts. It is a common finding resulting from obstruction by chronic inflammation and epithelial metaplasia.

M4 - HYDATID CYSTSThis specimen is from a patient with a history of hepatic hydatid cyst rupture. You see multiple, white colored, different sized cysts embedded in peritoneal fat tissue. These are dense fibrous capsules enclosing true cysts. This membrane-like structure represents the inflamed fibrous tissue, which is the result of host reaction. Some of these capsules are opened and inside them you can see the semi - opaque, soft outer layer of the hydatid cyst membrane (the cuticle). You can also see small, translucent cysts - the daughter cysts.

M5 - SEROUS PAPILLARY CYSTADENOMA OF THE OVARYThis is a unilocular cyst. The cyst wall is very thin, almost semi- transparent to light. The inner surface is smooth and glistening except for the small intracystic papillary formations.

M6 - SEROUS PAPILLARY CYSTADENOCARCINOMA OF THE OVARYThis is a multiloculated cystic ovarian tumor with minor solid components. Papillary structures are more abundant and in places, heaped up. There are also solid masses with cauliflower like appearance.

M7 - BENIGN CYSTIC TERATOMA OF THE OVARY (DERMOID CYST)This is a unilocular cystic tumor containing hair and cheese like brownish sebaceous material. The cyst wall is thin inside is reminiscent of skin, only on one pole you see solid area of heterogenous, variegated appearance. This is a predominantly cystic tumor with a small solid component as opposed to testicular teratoma which is a predominantly solid tumor with small cystic areas.

M8 - TRANSlTIONAL CELL CARCINOMA OF URINARY BLADDERYou see a cystectomy specimen. You see exophitic tumors composed of tiny, finger-like papillary structures growing from the bladder wall into the lumen.

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M9 - ENDOMETRIAL POLYPSYou see two hysterectomy specimens with large polyps filling the uterine cavities. The polyps grow from the upper portion (fundus) of the endometrium. One is solid, the other is predominantly solid with small cystic areas.The color change seen on the free tips is due to trauma and bleeding.

M10 - MULTIPLE (INFLAMMATORY) POLYPS – COLONA part of this colonic resection specimen has an atrophic mucosa, on the other (distal) half, you see multiple, small, elongated polypoid growths. The normal mucosa is practically absent in this area. The appearance of these polyps are different from the neoplastic polyps seen in colon cancer specimen. These are not neoplastic polyps.

M11 - COLON CANCERThere are two examples: in both, you see tumors with both exophytic and endophytic growth: raised – heaped up borders with central ulceration. Only on cut section you realize their invasive character: Central parts are ulcero-infiltrative and tumor seems to invade muscle layers of the bowel wall. In both, next to the tumor you see pedunculated polyps, as coarsely lobulated structures attached to the bowel wall with slender stalks.

M12 - LEIOMYOMA NODULES – UTERUSIn this very large specimen, you may not understand that the organ is uterus because it is so large and distorted by tumor nodules. You see the cut section three tumor nodules of variable sizes are apparent: the nodules have solid, white, fibrillary appearances, somewhat reminiscent of the surrounding myometrium. You see no capsules, but they have well-defined borders.

M13 - RENAL CELL CARCINOMA In this box, you see different examples of renal cell carcinoma. Cut sections of kidneys have bright yelow to grey white solitary tumors with sharply defined or irregular margins. You see a well demarcated round mass near one of the poles in one. It is confined within the kidney capsule, but bulge into surrounding fat tissue. Another example has again a rounded but more irregular border, it is a multinodular tumor which bulges into calyces and pelvis. Another example has a tumor that grows in a multinodular fashion replacing most of the renal parenchyma and also invading the perirenal fat. See the areas of necrosis within some of the tumors. Notice areas of central stellate fibrosis, cystic change and haemorrhagic areas.

M15 - MALIGNAT FIBROUS HISTIOCYTOMAYou see the skin covering the muscle and soft tissues (of the thigh). A large fungating growth can be seen on the surface. On cut surface, you can see the cancer is infiltrating the soft tissues, also permeating the muscle. It is a fleshy, coarsely nodular tumor. It has more “pushing” borders when compared to irregular borders of breast cancer. This is just deceptive, local invasion is always found in macroscopically well bordered areas.

M16 - TUMOR METASTASES – PERITONEUMThis is from a patient who had a very aggressive ovarian cancer. On the peritoneal fat tissue, you see multiple rounded masses of different sizes. These are not encapsulated but seem to be well demarcated macroscopically. Thay have variegated colors, the neoplasm was a malignant mixed tumor.

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M18 - TERATOMA OF TESTISInguinal orchiectomy specimens show enlarged testicle in huge dimensions. Cut surface displays a variegated appearence. It is a gray white tumor with some solid and multiloculated cystic areas. The compresed normal testis cannot be seen.

M19 - SEMINOMA OF TESTISOne inguinal orchiectomy specimen shows a very enlarged testis. There was a serous fluid between the layers of tunica vaginalis. The cut surface of the testis shows a large homogenous, lobulated neoplasm of grayish white color. The tumor has barely recognizable very small foci of necrosis (soft,yellow colored areas). A compressed testicular tissue could hardly be seen at one side of the tumor. Tunica albuginea is not penetrated but there is marked vascular congestion. Another example shows a nearly normal sized testis with a white, lobulated, solid tumor in the parenchyma. Although the sizes of the tumors are different, appearence on cut sections are very similar.

M20 - TERATOCARCINOMA OF TESTISThis is an inguinal orchiectomy specimen with large tumor replacing the entire testis and invading the testicular tunics. Cut surface displays a variegated appearence similar to a pure teratoma : you can see cystic multiloculated areas and solid areas with different textures, but this tumor also has the friable gray white appearence and extensive necrosis.

PATHOLOGY LABORATORY GUIDE FOR MICROSCOPIC EXAMINATION OF SLIDES

PATHOLOGIC DIFFERENTIATION of MALIGNANT AND BENIGN TUMORS - MICROSCOPY

TTM- THYROID TUMOR MIX (ADENOMA, PAPILLARY CARCINOMA OF THE THYROID WITH LYMPH NODE METASTASIS) There are three different sections on this slide. One is from the adenoma of thyroid, the other two are from a cancer. Both patients were females in their thirties with thyroid masses. First look at the adenoma. You see a definite fibrous capsule, normal thyroid is seen compressed around the tumour. The tumor is composed of larger follicles in this sample. It may have smaller follicles most of the times. The tumor cells are very similar to normal thyroid follicle cells.Compare the nuclei and celluler appearance of both. They are very similar. Then, look at the cancer. It infiltrates the thyroid follicles and also the surrounding tissue around thyroid. Papillary structures are very abundant. They have fibrovascular cores with overlying neoplastic cells. There are also solid masses of neoplastic cells and at places, follicle like structures. The nuclei of tumor cells are much larger than normal cells, but they are not hyperchromatic. Third, examine the metastatic cancer. You can see the normal structure of the lymph node in some areas but most areas are occupied by a metastatic carcinoma. Examine the histologic appearance of this carcinoma and compare it with the original papillary carcinoma.

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S-8 FIBROADENOMA This is from a young woman with a round, mobile brest mass. The mass is not encapsulated but very well demarcated. Look at the slide macroscopically. You will see its round homogenous appearance. Microscopically, this is a tumor composed of two components: a fibrous component which looks like the ordinary odematous fibrous tissue, and duct or cleft like structures lined by double layer of epithelial cells. Both the fibrous and the epithelial components have bland, almost “normal” nuclei. You will see compressed and atrophic breast acini around the tumor.

S-19 BREAST CARCINOMA This is from the mastectomy specimen of an elderly lady with a hard mass. You cannot see normal breast tissue but abundant fat tissue, because the patient was old and obese and much of the brest mass was fat tissue. You see the infiltrative cancer in the fat tissue. It has a very irregular border. You see small groups or cords or gland – like structures or solid masses of tumor cells. Pleomorphism is not prominent. Macroscopically, the tumor was very hard when compared to the surrounding breast tissue. This extreme firmness is due to marked desmoplasia in the tumor stroma. You see it as a pink colored fibrotic area in the center of the tumor.

D-10a METASTATIC CARCINOMA-LYMPH NODE This slide is prepared from an enlarged axillary lymph node from the mastectomy specimen. You can see the normal structure of the lymph node in some areas but most areas are occupied by a metastatic carcinoma. Examine the histologic appearance of this carcinoma and compare it with the original breast carcinoma.

R-10 LEIOMYOMA You have seen the macroscopic specimen. A 42 year old woman who had complaints of irregular shedding and dysmenorrhoea, underwent hysterectomy. Uterus was enlarged and irregularly nodular. Many firm, round, white nodules were found in the myometrium. You see a section prepared from one of these nodules. You see no capsule, but there is a well-defined border from the surrounding myometrium.Tumour is composed of fusiform cells with elongated nuclei which form bundles running at various angles( you can see some bundles in cross section, others in longitudinal section). Normal myometrium is seen compressed around the tumour. The normal myometrial cells are seen in more parallel bundles. The tumor cell bundles are seen in a more haphazard fashion. Other than that, the tumor cells are very similar to normal smooth muscle cells.Compare the nuclei of the tumour with that of the normal myometrium. They seem very “normal” in appearance.

V-39 MALIGNANT FIBROUS HISTIOCYTOMA You have seen the macroscopic specimen. It was a rapidly growing tumour removed from the thigh of a 62 year old male. You can see the cancer is infiltrating the fat tissue, there is also the muscle. It seems to have “pushing” borders when compared to irregular borders of breast cancer. Look carefully and you will see invasion in the periphery of the tumor. The tumour composed of highly pleomorphic cells: there are fusiform cells arranged in whorls, rounded mononuclear cells with foamy cytoplasm, multinucleated cells. Anaplasia is very prominent. The cells have very pleomorphic, hyperchromatic nuclei with frequent typical and atypical mitoses. Note the very coarse chromatin in clumps and very irregular nuclear shapes. Note the necrotic area within the tumour.Try to see the skeletal muscle and adipose tissue invaded by the tumour.

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MORPHOLOGIC DIAGNOSIS OF TUMORS AND TUMOR - LIKE LESIONS

Dx-ECTOPIC (HETEROTOPIC) PANCREAS IN STOMACH This is also called a choristoma. It is a rest of normal tissue in an abnormal location. Is was an asymptomatic mass and an incidental finding. A 56 year old male patient presented with an abdominal mass. Endoscopic examination of stomach was normal except for a small nodule in the antrum. With CT and US examination, the patient was found to have a primary liver tumor which caused the abdominal mass. When his liver tumor was resected at operation, the small nodule in the antrum was also removed. Macroscopically the nodule was 0.8cm in diameter and covered with mucosa.The section is prepared from this nodule. Microscopically, you see a nodule of pancreatic tissue in the submucosa and overlying normal gastric mucosa. The pancreatic tissue is composed of closely packed acini and ducts lined with columnar epithelium – just like the normal exocrine pancreas. There is mild edema and inflammation around the nodule.

D-26 HAMARTOMA This is a non-neoplastic lesion. The microscopic slide is prepared from a bulky mass located in the hard palate of a young male patient. Note somewhat proliferated keratinized squamous epithelium lining the surface of this particular mass. Beneath the surface epithelium, there is abundant collageneous connective tissue containing markedly proliferated but disorganized blood vessels in small diameter (capillaries). The lumina of some capillaries are dilated but most of the remaining capillaries are slitlike vascular structures lined with swollen endothelial cells. You may see mononuclear inflammatory cell infiltrate, extravasated erythrocytes, and hemosiderin laden macrophages around capillaries.

D8- ADENOCARCINOMA OF COLON This slide is prepared from a colon resection material with an ulcerovegetating carcinoma.If you examine whole surface of the section you will notice that on one side of the section normal colonic mucosa can be seen.When you move your slide towards the opposite side you will see the adenocarcinoma.It is composed of irregular glands with atypical epithelium.The cells of this neoplastic epithelium have large pleomorphic hyperchromatic nuclei. Also see mucin pools in stroma. This is a well-differentiated tumor because it is recognizable as adenocarcinoma, it forms glands and secretes mucin. You can see inflammatory cell infiltration in the stroma of the tumor and also around the tumor. Notice that the tumor infiltrated the submucosa. Try to find the normal colonic mucosa and compare the mucus content and nuclear size of its epithelium with that of the cancer.

K-22 SQUAMOUS CELL CARCINOMA-LARYNX These samples are from the laryngeal cancer of a 47 year old male smoker who complained of difficulty in swallowing and hoarseness. Macroscopically the tumour was an ulcerating-fungating friable mass that arose from left vocal cord and extended centrifugally. This slide is prepared from the outer border of the tumour. You can see luminal surface lined by squamous epithelium. The edematous stroma beneath the epithelium is invaded by the tumour. The tumour has highly differentiated areas where squamous cells with large eosinophilic cytoplasms form nests with horn pearls in them. 22

In these areas, you can recognize it as a squamous cell carcinoma because it resembles normal squamous epithelium with intracellular bridges and tendency for keartinization. In less differentiated areas neoplastic cells having pleomorphic, hyperchromatic nuclei and scanty cytoplasms,invade the stroma forming small groups and chords – you cannot recognize the squamous nature of the tumor in these areas. There is lymphocytic infiltrate in and around the tumour.

V-17 CHONDROSARCOMA This a malignant tumor which produces cartilage. Your slide belongs to a 46 year old woman who was admitted to the hospital with a complaint of a rapid growing mass around her pelvic bone. Her roentgenogram demonstrated a large lobulated mass with evidence of calcification. The mass appeared to arise from the wing of the left ilium. Hemipelvectomy was performed. Macroscopically, the tumour was 12x8x7cm in size and it invaded soft tissues. The cut surface was glistening and showed focal calcification. In your slides you are going to see a tumor quite similar to a hyaline cartilage tissue. If you look closely you will notice that the neoplastic cells which are embedded within basophilic matrix are plump and in contrast to mature chondrocytes two or three of them share the same lacunae. You may also notice the pleomorphism of the neoplastic cells.

D-25 TERATOMA This section is prepared from an ovarian tumour removed from a 32 year old woman. This tumour had a smooth external surface and predominantly solid but partially cystic white to tan in color and areas of cartilage could be recognized on its cut surface. Microscopically you see various sized cysts and various tissues scattered among them. Examine and differentiate variable types of tissues. They are all mature. You can see hyaline cartilage, nests of squamous cells with foci of keratinization in the center, glandular structures fibrous tissue, smooth muscle and nodular masses of mesencymal tissue (abundant proliferation of spindle cells with fine chromatin and scanty cytoplasm). Do you expect this tumor to behave in a benign or malignat fashion?

0-25 WILM'S TUMOR (NEPHROBLASTOMA) Mother of a one year infant felt a palpable mass in the abdomen of her baby. A tumor was diagnosed radiologically and then nephrectomy was performed. Grossly, the kidney appeared as huge irregular mass .The cut surface consisted mostly of variagated solid tumor mass with areas of necrosis and hemhorrage, renal parenchyma could only be seen at one pole of the kidney. Microscopic section includes only a cellular tumor, you do not see adjacent kidney parenchyma. This tumor is composed of three different cell types. The characteristic features of the tumor are 1-compact masses of primitive - undifferentiated cells with round or oval hyperchromatic nuclei and scanty cytoplasm (blastemal cells), 2- which form occasional abortive tubules and glomerulus –like structures (epithelial differentiation), 3-intermixed areas of immature spindle shaped cells, which represent areas of mesenchymal differentiation –they resemble primitive muscle cells. (What do you name a tumor that shows differentiation of a single cell line into parenchymal cells representative of more than one germ layer? Remember that ....blastomas –the so called “small round blue cell tumors of childhood” can show such features.) You can see both single cell necrosis and extensive necrosis.

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PATHOLOGY ( LABORATORY ) of INFECTIOUS DISEASES - MACROSCOPY

HYDATID CYSTSThis specimen is from a patient with a history of hepatic hydatid cyst rupture. You see multiple, white colored, different sized cysts embedded in peritoneal fat tissue. These are dense fibrous capsules enclosing true cysts. Some of these capsules are opened and inside them you can see the opaque, soft outer layer of the hydatid cyst membrane (the cuticle). You can also see small, translucent cysts - the daughter cysts.

HEPATIC HYDATID CYSTSThis patient underwent partial hepatectomy (lobectomy) for hydatid disease. You can see hydatid cyst cuticular and vegetative membrane and cysts embedded in the liver parenchyma. An additional specimen shows the fibrous capsule around hydatid cyst. This membrane-like structure represents the inflamed fibrous tissue, which is the result of host reaction.

PULMONARY TUBERCULOSISThis surgical specimen, represents fibrocaseous tuberculosis. Lesion is located at lung apex: a compressed cavity partially lined by yellow - gray caseous necrotic material and walled off by white, solid fibrous tissue. Around the cavitary lesion, there are yellow colored peribronchial infiltrates and yellow colored foci in the consolidated lung which represent dissemination of infection (non - cavitary tubercules with caseous necrosis). This is endobronchial dissemination of apical tuberculosis.

MILIARY TUBERCULOSISThese specimens : lungs, heart, liver, spleen, and kidneys are from an infant who died of disseminated tuberculosis. You can see multiple, small (usually pin - point to a few millimeters), yellow - white, distinct foci disseminated in the organs. This miliary seeding is especially prominent in the lungs and spleen. You can see fewer lesions in kidneys and in liver but none in the heart. There is congestion in all of the affected organs (dark red - brown color). [[ The dark colored areas on the costal surface of lungs and on the cut surface of liver are fixation artifacts ]]

TUBERCULOUS PYELONEPHRITISThe kidney is slightly enlarged with irregular nodular cortex. The cut surface shows multiple round yellowish soft cavities in the parenchyma. These yellowish foci are representative of caseous necrosis. See the soft friable material (caseous necrosis) filling the pelvis and calyces.

MICROSCOPY

E-8,LUNG TUBERCULOSIS, TUBERCULOUS LYMPHADENITISE-8 :A 54 year - old smoker male patient, had a history of malaise, night fever and weight loss. On chest x-ray, he had a central mass in his right lung, an apical cavity and multiple small opacities. Mediastinal lymph nodes were enlarged. After a diagnosis of squamous cell carcinoma bronchoscopic biopsy, he underwent pneumonectomy and mediastinal lymph node dissection. Lung harboured a central carcinoma and apical + disseminated tuberculosis. The lymph node specimens had multiple variously sized gray-white foci on cut surface. The slides have both lung and lymph node sections on them.

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In the lung, you will see granulomas composed of epitheloid histiocytes , Langhans type of giant cells, areas of caseation necrosis. Some granulomas are surrounded by lymphocytic infiltrates. In some areas you will see amorphous eosinophilic granular material with cellular debris which represents large and confluent granulomas with extensive necrosis. You may see fibrous tissue surrounding some granulomas. Wherever recognizable - not destroyed by granulomas- the lung tissue shows interstitial mononuclear inflammatory call infiltrate. Also near the granulomas, you can recognize numerous multinucleated plump histiocytes-foreign body type giant cells- which contain cholesterol clefts. Compare them with Langhans giant cells. Lymph node shows several round, nodular structures which are granulomas. Try to find Langhans type of giant cells and areas of caseation necrosis seen in the center of some of the granulomas.

E-6-c ACTINOMYCES, (Tonsil)These sections are prepared from a tonsillectomy specimen of a patient with cronic tonsillitis. Tonsillar crypts were filled with yelowish white granular material macroscopically. On microscopic examination of PAS- stained tissue sections, you will see prominent lymphoid follicular hyperplasia with enlarged, pale staining germinal centers. Tonsillar crypt epithelium is eroded in some areas and infiltrated by inflammatory cells in other areas. Within the tonsillar crypts, There are numerous magenta- colored (due to PAS- stain) bacterial colonies surrounded by polymorphonuclear leucocytes. Colonies consist of intertwined thread-like filaments capped by tiny eosinophilic clubs in a radiating pattern. They have this typical sun - burst pattern microscopically, and are diagnostic of actinomyces infection.

E-4 MOLLUSCUM CONTAGIOSUM, (skin)These sections are prepared from one of he multiple skin colored pruritic papules with umbilicated centers on the trunk of a 6 year old boy. You can see a cup-shaped lesion with distinct edges in the epidermis. Hyper plastic epidermis has grown down ward to dermis in lobules in the center of the lesion. In the stratum granulosum and stratum corneum , you see homogenous red , large cytoplasmic inclusions which displace the nuclei of cells. These inclusions, called "molluscum bodies" are aggregates of virions. They are pathognomonic for molluscum contagiosum.

E-3 CYTOMEGALOVIRUS (CMV) INFECTION; lungThis slide is prepared from the lung tissue of a premature neonate. She developed hepatosplenomegaly and pneumonitis and died within a week. At autopsy , the lungs showed patchy consolidation. Cut section revealed slightly elevated granular , gray and red to yellow appearing areas. In this slide you see large homogenous pink appearing areas of necrosis. In general alveolar walls are thickened and within the alveolar spaces you see markedly enlarged lining cells with large pleomorphic nuclei harboring basophilic intranuclear inclusions. The inclusions are surrounded by a clear halo sharply demarcating them from the nuclear membrane. (Owl’s eye!) The pleura is thickened , shows lymphocytic cell infiltration and dilated vessels.

E-9-b CANDIDIASIS, tongueThese sections prepared from the tongue of an immuno suppressed patient who died of leukemia. He had oral trush-white fluffy membranes which leave an irritated underlying mucosa when detached. The slides are stained with Periodic Acid-Schiff (PAS) method which stains mucopolisacharides purplish-red. You can see the squamous epithelium of tongue is thicker than normal and shows keratinization

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(appearing pale pink with PAS stain ). Cytoplasms of some squamous cells contain PAS (+) material (glycogen). On the surface of the papillae , you can see dense purplish clumps of pseudohyphae from which small yeast forms (blastospores) bud off. These are Candidae.

E-14-a ECHINOCOCCUS GRANULOSUS INFECTION ; liverE-14-b ECHINOCOCCUS ALVEOLARIS INFECTION ;brainE-14-a : A 38 year old man with fever, right upper quadrant pain and mass was operated with a presumptive diagnosis of liver absess. A soft, white cyst filled with pus was easily shelled out from the surrounding fibrotic tissue. This is an example of hydatid cyst with bacterial superinfection. As the inner germinative membrane and daughter capsules are destroyed by infection + lytic enzymes of neutrophil leucocytes, you can only see the thick, multi - laminated outer membrane - the cuticle. Within the lumen, there are neutrophil leucocytes, fibrin, necrotic debris. You will see reddish colored round structures which represent degenerated membrane and scolices undergoing calcification both in the lumen and in the laminated membrane.E-14-b : A 32 year old woman with a complaint of headache, vomiting , dizziness and diplopia was admitted to our hospital. He was evaluated as having increased intracranial pressure. CT revealed a multicystic mass with an enhancing rim at the left temporal lobe. He underwent decompression surgery. In this slide you see multilocular alveolar cysts within the compressed brain tissue. Examine the wall of the cysts which are composed of laminated membrane and darker inner germinal layer , without scolices. Notice the large necrotic areas especially around the cysts. Note the heavy inflammatory cell infiltration (lymphocytes and plasma cells) around these structures.

E-20 OXYURIS VERMICULARIS - appendixThese sections are from the appendix of a 15 year old boy who was operated for acute severe right lower abdominal pain. You can see edema, sparse inflammatory cell infiltrate and hyperplasia of the lymphoid tissue of appendix. In the lumen , you see many worms cut in various planes. The outer eosinophilic amorphous coat consists of chitin within which the viscera , surrounded by a clear space , are visible.

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HEMATOPOETIC SYSTEMS AND RELATED DISORDERS COURSE

SLIDES YOU ARE GOING TO EXAMINE IN THIS LABORATORY SESSION

I-1 CHRONIC NON SPESIFIC LYPHADENITIS Organ: Lymph node CASE :A-6-year-old girl who had frequent attacks of acute tonsillitis developed a non-tender, mobile enlargement of a cervical lymph node, Biopsy was performed to rule out malignancy.PATHOLOGICAL FINDINGSGross findings: HE-1 Diffusely enlarged lymph node with the size of 3x2x1 cm. The cut section appear as homogeneous and white in color. Microscopic findings:The microscopic sections reveal that the architecture of the node is preserved . The lymphoid follicles are enlarged with prominent germinal centers. The germinal centers are pleomorphic, that is they contain lymphocytes in different stages of differentiationand tingible body macrophages. Compare the features of this slide wjith those of the next slide (t-8) and try to see the differences between them.

HE-2 LYMPHOMAORGAN: SpleenGross Findings: In the cut section of the spleen, numerous white-tan colored, slightly elevated nodular masses can be seen.(approximately 0.6-0.8 cm. in dimension). This leads to diffuse enlargement of the spleen.Descriptive notes: These nodular masses are formed by neoplastic proliferation of small B lymphocytes .

T-4 FOLLICULAR LYMPHOMAOrgan: Lymph nodeCASE:A-55-year old woman with cervical lyrnphadenopathy underwent anexcisional biopsy .PATHOLOGICAL FINDINGSMicroscopic findings: At low magnification, uniform sized, in back to back configuration follicules are observed in the lymph node. When you examine carefully you will notice mainly one cell type found in these follicular structures. This cell type is small cell with irregular or cleaved nuclear contours and scant cytoplasm named as centrocytes. There are scattered large cells with multiple nucleolies in between. Is there any tingible body macrophages in these follicles? Please try to answer.

I-5 HODGKIN LYMPHOMA-MIXED CELLULAR TYPEOrgan: Lymph nodeCASE:A-13-year old boy with supraclavicular lymphadenopathy underwent an excisional biopsy.PATHOLOGICAL FINDINGSMicroscopic findings:The normal architecture of the lymph node is effaced. The capsule of the lymph node is thickened .There is a diffuse type of infiltration in this lymph node. This infiltration consists of neoplastic cells called Reed-Sternberg(R-S) cells and reactive cells. Some of R-S contain bilobated nuclei and prominent eosinophilic nucleoli. These cells resemble to owl eyes. Reactive cells are composed of lymphocytes, histiocytes, plasma cells and eosinophils.

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T-8 SMALL LYMPHOCYTIC LYMPHOMAOrgan: Lymph nodeCASE ;A 50-year-old man presented with large non-tender lyrnphadenopathy consisting of a chain of lymph nodes in his right cervical region. He complained of weight loss and fatigue for the last three months. PATHOLOGICAL FINDINGSMicroscopic findings:This slide is prepared from the biopsy of the enlarged lymph node. The normal architesture of the lymph node is destroyed by a diffuse infiltration of monomorphic cells. The marginal sinuses are filled with malignant cells, which have dark staining, monotonous nuclei with little cytoplasm. The capsule of the lymph node is generally infiltrated by the same cells which is another criteria of malignancy.

I -.21 MULTIPLE MYELOMAOrgan: Bone-vertebraCASE:A-67 year old female presented with severe back pain. X - ray showed fracture at T-7 vertebra. This area was operated.PATHOLOGICAL FINDINGSMicroscopic findings:.Microscopic section shows cartilage, soft tissue, and neoplastic tissue fragments. Neoplastic tissue is composed of mature appearing plasma cells. Intranuclear inclusions ( Dutcher bodies ) and intracytoplasmic inclusions ( Russell bodies ) are seen.

HE-2: LYMPHOMAORGAN: SpleenGross Findings: In the cut section of the spleen, numerous white-tan colored, slightly elevated nodular masses can be seen.(approximately 0.6-0.8 cm. in dimension). This leads to diffuse enlargement of the spleen.Descriptive notes: These nodular masses are formed by neoplastic proliferation of small B lymphocytes .

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MUSCULOSKELETAL SYSTEM AND RELATED DISORDERS

NON-NEOPLASTIC DISEASES

V-23 OSTEOPOROSIS:Osteoporosis is the increased porosity of the skeleton due to reduction in bone mass. It is mostly seen in senile and postmenopausal patients. Your slide belongs to a 75 year-old woman who admitted to hospital with a femur fracture. X-ray examination revealed a fracture at the neck of the femur and osteoporotic changes. She had an operation and a prosthesis was replaced in her hip.Microscopic findings: You will easily notice that the bone trabecula is thinned and lost their interconnections (which is the reason for the fractures). Also you will see that the bone marrow is mostly replaced by fat tissue. This is not a feature of osteoporosis but a finding of senility.

V-12 NON-SPECIFIC OSTEOMYELITIS:Osteomyelitis is the inflammation of bone and marrow. Altough all kinds of microorganisms can cause osteomyelitis the most common etiologic agents are pyogenic bacteria and mycobacteria. Your slides belong to a 12 year-old boy who admitted to hospital with a complaint of fever, severe local tenderness and pain at the lower end of left femur. Blood culture revealed S. aureus. X-ray showed a lytic focus of bone destruction surrounded by a zone of sklerosis.Microscopic findings: Note that normal histology of bone tissue is disturbed. Instead of marrow, you see dense inflammatory cells mainly neutrophil leucocytes and necrosis. You may also see lymphoid aggregates.

NEOPLASTIC DISEASES

BONE AND CARTILAGE FORMING TUMORS

V-15 OSTEOID OSTEOMA:This is a benign bone tumor which is less than 2 cm in diameter and usually occurs in teens and at the age of twenties. They can arise in any bone but 50% is in femur and tibia and usually involves the cortex. They are painful lesions and the pain is dramatically revealed by aspirin. Your slide belongs to a 15 year-old boy who admitted to the hospital with a complaint of localised pain at his left shoulder. X-ray revealed a radiolucent lesion of 1 cm in diameter at the metaphysic of the humerus. He went on an operation with the clinical diagnosis of osteoid osteoma.Microscopic findings: You will see a circumscribed lesion which is composed of randomly interconnecting trabecula of woven bone that are rimmed by osteoblasts. The stroma surrounding the tumor bone consists of loose connective tissue that contains many dilated vessels.

V-17 CHONDROSARCOMA:This is a malignant tumor which produces cartilage. Usually seen over the age of 40. your slide belongs to a 46 year-old woman who admitted to hospital with a complaint of a rapid growing mass around her pelvis. Her X-ray demonstrated a large lobular mass

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with evidence of calcification and ossification. The mass appeared to arise from the wing of left ilium. Hemipelvectomy is performed.Macroscopic findings: The size of the tumor was 12x8x7 cm and it invaded soft tissues. The cut surface was glistening and showed focal calcification.Microscopic findings: ın your slides you are going to see a tumor quite similar to a hyaline cartilage tissue. If you look closely you will notice that the neoplastic cells which are embedded witin basophilic matrix are plump and in contrast to mature chondrocytes two or three of them share the same lacunae. You may also notice the pleomorphism of the neoplastic cells.

OTHERS

V-18 EWING SARCOMA:Ewing sarcoma is an uncommon malignant bone tumor composed of small, uniform, round cells belonging to a family of primitive neuroectodermal tumors of childhood. Your slides belong to a 12 year-old girl who admitted to hospital with a complaint of weight loss, fever, local tenderness and pain at the end of femur. X-ray showed a lesion at the lower end of femur which was characterized by cortical thickening and medullary widening and circumferential periosteal thickening (onion skin pattern).Macroscopic findings: The cut sections of the surgical material revealed a soft tumor which enlarged the medullary cavity. Cortex and periosteum were thickened.Microscopic findings: You will see a diffuse infiltration of tumor cells and a little amount vascular stroma among them. The neoplastic cells are small and uniform with round nuclei and small nucleoli and inconspicious cytoplasmic outlines. Some of you may see the rossette formation; tumor cells arranged around a secretory material.

V-19 GIANT CELL TUMOR: Giant cell tumor is an uncommon benign but locally agressive neoplasm. Its’ name comes from the osteoclast like giant cells disributed in the tumor. Your slides belong to a 45 year-old woman who admitted to hospital with femur fracture. X-ray showed a pathological fracture on the upper end of the femur. At the epiphysis there was an extensively destructive osteolytic tumor. Macroscopic findings: The cut section of the resected tumor showed multiple cysts, cortical destruction and areas of hemorrhagic necrosis.Microscopic findings: you will see a tumor composed of stromal cells and multinucleated giant cells resembling osteoclasts. Stromal cells have oval vesicular nuclei and scanty cytoplasms; these cells are the neoplastic cells of this tumor.

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RESPIRATORY SYSTEM AND RELATED DISORDERSCOURSE

SLIDES YOU ARE GOING TO EXAMINE IN THIS LABORATORY SESSION

INFECTIOUS DISEASES

K-24 Normal LarynxOrgan: LarynxThis section is prepared from an edematous but otherwise normal larynx. You can see that the ventricle is compressed as a result of edema of the false vocal cord. Try to see the striated muscle fibers. Try to find the area of respiratory epithelium which has undergone squamous metaplasia. You can see the seromucinous glands in the lamina propria and subepithelial mononuclear inflammatory infiltrate.

K-21 Laryngeal PolypOrgan: LarynxCASE:A-32 year old male teacher has hoarseness from 2 months. The ENT surgeon detect a nodule in his vocal cords and excised the nodule.

PATHOLOGICAL FINDINGSMicroscopic findings:You have seen this slide as edema. This section is prepared from a smooth, rounded, pedunculated nodule removed from the vocal cord of a 32 year-old male. You see a polipoid mucosal tissue covered by squamous epithelium. The stroma is composed of loose connective tissue infiltrated by inflammatory cells and extravasated erythrocytes. In some parts this stroma is dense, collagenous and stained deeply eosinophilic. This eosinophilic amorphous deposit represents the protein and solutes of edema fluid (exudate). But in some areas connective tissue cells seem to be forced apart by fluid and inflammatory cells appear to be suspended in clear spaces. (Transudate).

K- 5 PneumoniaOrgan: LungCASE:A 52 year old man who complained of persistent cough, foul smelling sputum, and shortness of breath, was admitted to our hospital. He was a heavy smoker of 36 years duration. He had dyspnea , mild cyanosis and fever. Despite treatment of a variety of antibiotics, pneumonic infiltration of right lower lobe persisted and the patient underwent lobectomy.

PATHOLOGICAL FINDINGSGross findings:HD-30 Macroscopic examination revealed patchy distribution of areas of consolidation (slightly elevated, firm ,grayish-red and yellow poorly delimited areas). Microscopic findings:This section is prepared from a consolidated area of this lobe. . The walls of the bronchi are intensely infiltrated with inflammatory cells and their lumina are filled with pus. In addition to the features you see alveoli filled with pink homogenous fluid with few erythrocytes and polimorphonuclear leucocytes in it. You may also see alveolar histiocytes. Try to find areas where neutrophilic exudate is more prominent.

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K-6 TuberculosisOrgan: LungCASE:50 years old male patient who complained of cough and night sweet. Chest x-ray revealed bilateral shadow appeareance in the lung. He undervent lobectomy.

PATHOLOGICAL FINDINGSGross findings:HD-21 Macroscopically, lobectomy specimen has irregular, cystic nodular area filled by cheesy material ( grey- white necrosis foci). Microscopic findings: You’ll see several large granulomas with central caseification necrosis. These granulomas are confluent, markedly surrounded with lymphocytic rim. In high magnification you’ll recognize that granulomas are made of epithelioid histiocytes and Langhans type multinucleated giant cells.EZN staining demonstrated pink (ARB positive) mycobacterium bacilli in the necrosis areas.

OBSTRUCTIVE AND INTERTITIAL DISEASES

K-3-11 CHRONIC BRONCHITIS AND BRONCHIECTASISOrgan: LungCASE (same case with K-5):A 52 year old man who complained of persistent cough, foul smelling sputum, and shortness of breath, was admitted to our hospital. He was a heavy smoker of 36 years duration. He had dyspnea , mild cyanosis and fever. Despite treatment of a variety of antibiotics, pneumonic infiltration of right lower lobe persisted and the patient underwent lobectomy.

PATHOLOGICAL FINDINGSGross findings:Macroscopic examination of the lower lobe revealed patchy distribution of areas of consolidation (slightly elevated, firm ,grayish-red and yellow poorly delimited areas) and on cut surface markedly distended bronchi producing an almost cystic pattern. The lumina of the bronchi were filled with suppurative exudate. The lung parenchyma showed patchy atelectasis , hemorrhage and areas of consolidation. Microscopic findings: On microscopic examination you see markedly distended bronchi which appear crowded together with compression of the intervening lung parenchyma. The walls of the bronchi are intensely infiltrated with inflammatory cells and their lumina are filled with pus. You may see desquamation of their lining epithelium and in some areas necrotizing ulceration of the bronchial wall. Fibrosis of the bronchial walls , hyperplasia of lymphoid follicles and hemosiderin laden macrophages are other prominent features.

K-12 HYALINE MEMBRANE DISEASEOrgan: LungCase:A preterm newborn baby of a diabetic mother is delivered..Half an hour after delivery the baby 's breathing deteriorated and over the next few hours his dyspnea gradually worsenedwith cyanosis, wheezing and intercostal retraction. He did not respond to oxygen administration and ventilatory treatment and died 12 hours after his birth.

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PATHOLOGICAL FINDINGSGross findings:His lungs seemed somewhat smaller then normal size, solid airless and reddish purple (liver-like). Microscopic findings: On low power microscopic examination lung tissue has apperance of solid tissue.You see small crumpled alveoli and over extended airways with prominent type II pneumocytes or peripheral band of eozinophilic granular material called hyaline membranes. The membrane are made up of fibrin and cell debris derived from type II pneumocytes.

K - 14 SARCOIDOSISOrgan: LungCASE:Shortness of breath, cough, and chest pain were the presenting symptoms of a 32-year old male to the hospital. Chest radiograph showed both bilateral hilar lymph node enlargement and pulmonary infiltrates. During mediastinoscopy, tiny, white nodules were determined on the surface of the visceral pleura. PATHOLOGICAL FINDINGSMicroscopic findings: This section is prepared from the mediastinoscopic biopsy of this patient. The lung architecture is partially replaced by multiple isolated or confluent aggregates of well-formed granulomas. Please try to identify the distribution pattern of the granulomas, that is along the lymphatic route. They are situated subpleurally, along the septa and around the bronchovascular bundles. Epithelioid cells with a few scattered multinucleated giant cells of Langhans and foreign body type form the largest part of the granulomatous structures. Granulomas lack significant peripheral lymphocytic rim but have abundant collagen deposits surrounding them. They are tight, well formed and non-caseating.

NEOPLASTIC DISEASES

K-22 SQUAMOUS CELL CARCINAMAOrgan:Larynx CASE:A 47 year-old male patient complained of difficulty in swallowing and hoarseness. A laryngeal tumor was found.

PATHOLOGICAL FINDINGSGross findings:Macroscopically the tumor was an ulcerating, fungating friable mass that arose from left vocal cord and extended centrifugally. Microscopic findings: This slide is prepared from the outer border of the tumor. You can see luminal surface lined by metaplastic squamous epithelium. The edematous stroma beneath the epithelium is invaded by the tumor. Tumor has highly differentiated areas where squamous cells with large eosinophilic cytoplasms form nests with horn pearls in them In less differentiated areas neoplastic cells having pleomorphic, hyperchromatic nuclei and scanty cytoplasm, invade the stroma forming small groups and cords. Notice the infiltration of lymphocytes and plasma cells.

K-8-c BRONCHIOLARALVEOLAR CARCINOMAOrgan: Lung

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CASE:Chest X-ray of a 42-year old male revealed bilateral multiple masses in the upper lobes of the lungs.

PATHOLOGICAL FINDINGS Gross findings:On the gross examination of the lobectomy specimens soft, slightly raised, yellowish multiple small nodules were seen.

Microscopic findings:Histologic sections prepared from lobectomy specimens disclose small neoplastic foci well deliniated from the surrounding lung paranchyma. The defining microscopic feature is the lepidic growth of the neoplasm, that is, growth along alveolar septa without destroying the underlying interstitial tissue. Minimal desmoplastic reaction and lymphocitic response is observed in the alveolar walls. In some areas neoplastic cells form papillary projections into the alveolar sacs Within the alveolar sacs you will discern some small papillary structures, neoplastic cells and foamy macrophages.

RS-1 SQUAMOUS CELL CARCINOMA Organ: LungCASE:A-56-year old heavy smoker male admitted to the hospital with cough, sputum and weight loss approximately 10 kg. in 2 months.Chest x-ray revealed solid mass in his right lobe. Lobectomy was done.

PATHOLOGICAL FINDINGSGross findings: There is a necrotic, solid, white-tan colored, 5x4 cm. in diameter tumoral mass in cental bronchus of the lobe. The other areas of the lung has patchy black discoloration(antracosis) and mucin accumulation in the bronchioles.

RS-2 ADENOCARCINOMAOrgan: LungCASE:A-61-year old female admitted to the hospital with cough, weight loss. Chest x-ray revealed coin lesion in the peripheral area of her right lobe. There is no smoking history. Lobectomy was done.

PATHOLOGICAL FINDINGSGross findings: There is a solid, well delinieated,white-tan colored, 3x2 cm. in diameter tumoral mass in periphery of the lobe.

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