Introduction to Introduction to pathologypathology

Dr. Amitabha Basu MDDr. Amitabha Basu MD

What is Pathology ?What is Pathology ?

It is the study It is the study ((logoslogos)) of the of the sufferings sufferings (pathos).(pathos).

It’s a laboratoryIt’s a laboratory

Basic Sciences

Clinical Medicine

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Various Divisions of Various Divisions of pathologypathology

1.1. Clinical PathologyClinical Pathology

2.2. Molecular PathologyMolecular Pathology

3.3. HematopathologyHematopathology

4.4. HistopathologyHistopathology

5.5. CytopathologyCytopathology

6.6. Blood bankingBlood banking

Clinical PathologyClinical Pathology

Automatic Analyzer

Clinical pathologyClinical pathology

►A branch of pathology concerned with A branch of pathology concerned with patient care.patient care.

Molecular PathologyMolecular Pathology

Molecular PathologyMolecular Pathology►A branch of pathologyA branch of pathology concerned concerned

with the with the study of the diseases and study of the diseases and mechanisms of disease on mechanisms of disease on a molecular a molecular or chemical levelor chemical level..

Human immunodeficiency virus, viral particles at Human immunodeficiency virus, viral particles at medium magnification adjacent to cell surface, medium magnification adjacent to cell surface,

electron micrograph.electron micrograph.

HematopathologyHematopathology

HematopathologyHematopathology►This branch deal with the This branch deal with the Disease Disease

of the Blood.of the Blood.

This peripheral blood smear is stained with the Wright's stain. (Leishman stain)

Here is a laboratory instrument Here is a laboratory instrument called a Coulter Counter called a Coulter Counter

CBC (complete blood count) : CBC (complete blood count) : from Coulter blood cell from Coulter blood cell

countercounter

Cytopathology: Cytopathology: Study of cellular Study of cellular change in the diseased tissuechange in the diseased tissue..

CytopathologyCytopathologyStudy of cellStudy of cell

Tissue composed of many cell of similar function

Two methods to obtain the Two methods to obtain the cellscells

1.1. Exfoliative cytologyExfoliative cytology ( collect and ( collect and examine the cell that falls –off from examine the cell that falls –off from the tissue)the tissue)

2.2. FNACFNAC (Fine needle Aspiration (Fine needle Aspiration Cytology): cell obtained with a fine Cytology): cell obtained with a fine needle. needle.

What is that mean ?What is that mean ?

►Exfoliated cells Exfoliated cells ( eg from ( eg from Cervix)Cervix) for for quick diagnosis quick diagnosis of malignancyof malignancy

►Stain Uses:Stain Uses:►Papanicolaou Papanicolaou

StainStain

Pap Smear

If there is malignancy- it will If there is malignancy- it will look like thislook like this

Cervical CytologyCervical Cytology► It helps in It helps in early diagnosisearly diagnosis of cancer of of cancer of

Uterine Cervix.Uterine Cervix.

So, you can prevent a cancer like

this!!

FNAC [ fine needle aspiration FNAC [ fine needle aspiration cytology ]cytology ]

Cells obtained from an abnormal mass in the body : EG Breast lump

Pathologist performing an FNAC Pathologist performing an FNAC from thyroid and breastfrom thyroid and breast

Aspirated Thyroid cells shows Aspirated Thyroid cells shows features features of malignancy : of malignancy : Aspirated cells Aspirated cells

stained with Giemsa Stainstained with Giemsa Stain

It is quick.

Less expensive

No hospital stay required

HistopathologyHistopathology

Study of tissueStudy of tissue

Tissue composed of many cell of similar function

Histopathology- a technique to identify a Histopathology- a technique to identify a disease by looking at the tissue!disease by looking at the tissue!

House of final diagnosis.House of final diagnosis.

► Tissue is collected and fixed with formalin- Tissue is collected and fixed with formalin- overnight- it takes time!.overnight- it takes time!.

► It is then embedded in paraffin and cut with It is then embedded in paraffin and cut with microtome- 3 micron thick.microtome- 3 micron thick.

► This thin tissue is then stained with This thin tissue is then stained with Hematoxiline & eosin( H&E) stain.Hematoxiline & eosin( H&E) stain.

► Following that it is mounted with DPX and Following that it is mounted with DPX and cover slip.cover slip.

Normal Squamous cell and Normal Squamous cell and Histopathology of Squamous cell Histopathology of Squamous cell

carcinoma.carcinoma.

Definition of histopathology:

Pathological Study of the minute structure, Pathological Study of the minute structure, composition, and function of diseased composition, and function of diseased tissues.tissues.

HistopathologyHistopathology

An important procedure to rule out An important procedure to rule out or confirm malignancy.or confirm malignancy.

Stain Used : Hematoxylin and Eosin Stain Used : Hematoxylin and Eosin StainStain

[ H & E ][ H & E ]

Biopsy Biopsy

►The removal and examination of a The removal and examination of a sample of tissue from a living body for sample of tissue from a living body for diagnostic purposes diagnostic purposes

Biopsy sample then sent to Biopsy sample then sent to the Histopathology the Histopathology

laboratorylaboratoryTissue were kept in the Formalin for Tissue were kept in the Formalin for

Fixation and to avoid autolysisFixation and to avoid autolysis

Frozen sectionFrozen section

►Paraffin section takes time---Paraffin section takes time---

► If you need a quick section…..we If you need a quick section…..we harden the tissue by freezing it…harden the tissue by freezing it…frozen section.frozen section.

Frozen SectionsFrozen Sections

►It is necessary to get a It is necessary to get a rapid rapid diagnosisdiagnosis of a pathologic process. of a pathologic process.

►The piece's are snap frozen in a cold The piece's are snap frozen in a cold liquid or liquid or cold environment (-20 to -cold environment (-20 to -70 Celsius).70 Celsius).

►Freezing makes the tissue solid Freezing makes the tissue solid enough to section with a microtome. enough to section with a microtome.

Cutting a frozen section. Cutting a frozen section. Cryostat. Cryostat.

Use of frozen section Use of frozen section technique. technique.

1.1. To check to presence of tumor in To check to presence of tumor in surgical resected ends, while surgical resected ends, while removing a tumor from the body.removing a tumor from the body.

2.2. To check for the presence of To check for the presence of metastasis tumor in lymph node.metastasis tumor in lymph node.

3.3. To identify fat.To identify fat.

This is not enough!This is not enough!

So we need special stains!So we need special stains!

Special steins and common UseSpecial steins and common UsePeriodic acid Periodic acid StainStain

Stain Stain GlycogenGlycogen

Storage disease, Storage disease, Ewing's sarcoma, Ewing's sarcoma, Candida.Candida.

Mucicarmine Mucicarmine Stain Stain

Stain Mucin Stain Mucin Identify Identify adenocarcinomaadenocarcinoma

Prussian blue Prussian blue reaction &reaction &

Perl's iron Perl's iron stain stain

StainStain

IronIronHemochromatosisHemochromatosis

Oil-O-Red stainOil-O-Red stain Stain Fat( in Stain Fat( in frozen frozen section)section)

Fatty LiverFatty Liver

Trichrome Trichrome stainstain

Stain Stain collagencollagen

Scar.Scar.

Special steins and common UseSpecial steins and common Use

leukocyte leukocyte alkaline alkaline phosphatase phosphatase (LAP) (LAP)

Stain Stain Neutrophils( Neutrophils( normally normally present)present)

LowLow in in Chronic Chronic Myeloid Myeloid LeukemiaLeukemia

The The myeloperoximyeloperoxidase (MPO) dase (MPO) stain stain

Identify Identify myeloid cellsmyeloid cells

Acute Acute Myeloblastic Myeloblastic Leukemia.Leukemia.

Blood BankBlood Bank

Blood BankBlood Bank►Optimal Blood Testing, Optimal Blood Testing,

Preservation and Utilization of Preservation and Utilization of Blood and blood products.Blood and blood products.

Donate Blood to save a lifeDonate Blood to save a life

Welcome once again to the Welcome once again to the world of Pathologyworld of Pathology

Why ? How ? Where ? = Answer this and you will get your diagnosis

How to study pathology ? How to study pathology ? EasyEasy

►Learn Learn ► WhyWhy is the disease = is the disease = EtiologyEtiology► What What are the typesare the types = Classification = Classification► HowHow the disease occur = the disease occur = PathogenesisPathogenesis► WhereWhere = = Morphological ChangeMorphological Change of the of the

organ organ effectedeffected► What happens then = What happens then = Clinical Clinical

significance.significance.

Follow this pattern and you will never forget pathology

Understanding of a few terms: and also Understanding of a few terms: and also

study pathology in this sequencestudy pathology in this sequence..

1.1. EtiologyEtiology2.2. PathogenesisPathogenesis3.3. MorphologyMorphology

1.1. Gross change of a diseased Gross change of a diseased organ/tissueorgan/tissue

2.2. Microscopical change of the tissue Microscopical change of the tissue and cells.and cells.

4.4. Functional Derangement and Functional Derangement and Clinical SignificanceClinical Significance

EtiologyEtiology

►Cause of the disease.Cause of the disease.►Example Example : Chronic Alcoholism is : Chronic Alcoholism is

the the etiology etiology of fatty liver. of fatty liver.

PathogenesisPathogenesis

Definition : Mechanism of disease Definition : Mechanism of disease formationformation

►Alcohol Alcohol produce injury to the liver cells , produce injury to the liver cells , following that Liver cells (Hepatocytes) following that Liver cells (Hepatocytes) become unable to metabolize Fatty acid.become unable to metabolize Fatty acid.

►And it accumulate in the liver cells And it accumulate in the liver cells to produce fatty liver. to produce fatty liver.

Pathogenesis : narrowing of the Pathogenesis : narrowing of the coronary artery : Myocardial coronary artery : Myocardial

Infarction.Infarction.

Morphology : 2 partsMorphology : 2 parts

1.1.Gross visible changeGross visible change of a of a diseased organ/tissue.diseased organ/tissue.

2.2.Microscopical changeMicroscopical change of of the tissue and cells.the tissue and cells.

Morphology: Morphology: GrossGross change in change in the diseased organ.the diseased organ.

Morphology: Morphology: MicroscopicalMicroscopical change in the tissue / cells change in the tissue / cells

Functional Derangement and Functional Derangement and Clinical SignificanceClinical Significance

Signs and Signs and SymptomsSymptoms

Evaluation Evaluation of theof the

Disease Disease PrognosisPrognosis

Cell and PathologyCell and Pathology

► Structural and Functional Change in Structural and Functional Change in the cell is the basis of all forms of the cell is the basis of all forms of organ Injury.organ Injury.

Rudolf Virchow

Father of Modern

Pathology

LearninLearningg

MUST KNOW AREA

GOOD TO KNOW AREA

NICE TO KNOW AREA

Thank you.Thank you.

Enjoy the subject and learn Enjoy the subject and learn it.it.