mediastinal pathology compartmental approach
TRANSCRIPT
![Page 1: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/1.jpg)
Arm
ed Fo
rces Institu
te of Path
olo
gy
Mediastinal Pathology: Mediastinal Pathology: Compartmental ApproachCompartmental Approach
Teri J. Franks, MDTeri J. Franks, MD
ChairmanChairmanDepartment of Pulmonary and Mediastinal PathologyDepartment of Pulmonary and Mediastinal Pathology
![Page 2: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/2.jpg)
Faculty Disclosure InformationAt the time of the VTC, At the time of the VTC, Teri J. Franks, MDTeri J. Franks, MD had no significant financial interests had no significant financial interests or relationships to disclose.or relationships to disclose.
As a provider accredited by the Accreditation Council for ContinAs a provider accredited by the Accreditation Council for Continuing uing Medical Education, the Department of Medical Education of The Medical Education, the Department of Medical Education of The Armed Forces Institute of Pathology must insure balance, Armed Forces Institute of Pathology must insure balance, independence, objectivity and scientific rigor in all its indiviindependence, objectivity and scientific rigor in all its individually dually sponsored or jointly sponsored educational activities. All faculsponsored or jointly sponsored educational activities. All faculty ty participating in a sponsored educational activity are expected tparticipating in a sponsored educational activity are expected to o disclose to the activity audience any significant financial intedisclose to the activity audience any significant financial interest or rest or other relationship (1) with the other relationship (1) with the manufacturer(smanufacturer(s) of any commercial ) of any commercial product(sproduct(s) and/or ) and/or provider(sprovider(s) of commercial services discussed in ) of commercial services discussed in an educational presentation and (2) with any commercial an educational presentation and (2) with any commercial supporters of the activity (significant financial interest or otsupporters of the activity (significant financial interest or other her relationship can include such things as grants or research supporelationship can include such things as grants or research support, rt, employee, consultant, major stock holder, member of speakers employee, consultant, major stock holder, member of speakers bureau, etc.). The intent of this disclosure is not to prevent abureau, etc.). The intent of this disclosure is not to prevent aspeaker with a significant financial or other relationship from speaker with a significant financial or other relationship from making a presentation, but rather to provide listeners with making a presentation, but rather to provide listeners with information on which they can make their own judgments. It information on which they can make their own judgments. It remains for the audience to determine whether the speakerremains for the audience to determine whether the speaker’’s s interests or relationships may influence the presentation with interests or relationships may influence the presentation with regard to exposition or conclusion.regard to exposition or conclusion.
![Page 3: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/3.jpg)
Main TopicsMain Topics
•• Clinical featuresClinical features•• Organization of lesionsOrganization of lesions
–– Mediastinal anatomyMediastinal anatomy–– Compartment approachCompartment approach
•• Selected lesionsSelected lesions–– Thymoma and thymic carcinomaThymoma and thymic carcinoma
![Page 4: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/4.jpg)
Mediastinal LesionsMediastinal LesionsClinical featuresClinical features
•• Uncommon, 1% of all tumorsUncommon, 1% of all tumors•• Infant to 83 years, mean 35.4 yearsInfant to 83 years, mean 35.4 years•• No gender biasNo gender bias•• 60% benign, 40% malignant60% benign, 40% malignant•• 60% symptomatic60% symptomatic
–– Chest pain, cough, dyspnea, dysphagia, superior vena cava syndroChest pain, cough, dyspnea, dysphagia, superior vena cava syndromeme
•• 97% can be detected on PA and lateral chest radiographs97% can be detected on PA and lateral chest radiographs•• Surgical resectionSurgical resection
–– Low operative morbidity and mortalityLow operative morbidity and mortality
![Page 5: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/5.jpg)
MediastinumMediastinumGross anatomyGross anatomy
•• BoundariesBoundaries–– Anterior: sternumAnterior: sternum–– Posterior: vertebral columnPosterior: vertebral column–– Superior: thoracic inletSuperior: thoracic inlet–– Inferior: diaphragmInferior: diaphragm–– Lateral: parietal pleuraLateral: parietal pleura
![Page 6: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/6.jpg)
![Page 7: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/7.jpg)
MediastinumMediastinumCompartmentsCompartments
•• AnteriorAnterior•• MiddleMiddle•• PosteriorPosterior
![Page 8: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/8.jpg)
MediastinumMediastinumCompartmentsCompartments
•• AnteriorAnterior
![Page 9: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/9.jpg)
MediastinumMediastinumCompartmentsCompartments
•• AnteriorAnterior•• MiddleMiddle
![Page 10: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/10.jpg)
MediastinumMediastinumCompartmentsCompartments
•• AnteriorAnterior•• MiddleMiddle•• PosteriorPosterior
![Page 11: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/11.jpg)
![Page 12: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/12.jpg)
![Page 13: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/13.jpg)
![Page 14: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/14.jpg)
MediastinumMediastinumDistribution of lesionsDistribution of lesions
•• AnteriorAnterior 50%50%•• MiddleMiddle 25%25%•• PosteriorPosterior 25%25%
![Page 15: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/15.jpg)
MediastinumMediastinumContentsContents
•• AnteriorAnterior–– ThymusThymus–– Lymph nodesLymph nodes–– Heart and pericardiumHeart and pericardium–– Ascending aortaAscending aorta–– BrachiocephalicBrachiocephalic vesselsvessels–– Superior and inferior vena cavaSuperior and inferior vena cava–– PhrenicPhrenic nervesnerves–– FatFat–– EctopicEctopic tissuetissue
![Page 16: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/16.jpg)
MediastinumMediastinumContentsContents
•• MiddleMiddle–– TracheaTrachea–– MainstemMainstem bronchibronchi–– EsophagusEsophagus–– Lymph nodesLymph nodes–– Descending aortaDescending aorta–– Pulmonary arteries and veinsPulmonary arteries and veins–– AzygosAzygos and and hemiazygoshemiazygos veinsveins–– Thoracic ductThoracic duct–– VagusVagus and and phrenicphrenic nervesnerves
![Page 17: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/17.jpg)
MediastinumMediastinumContentsContents
•• PosteriorPosterior–– Sympathetic gangliaSympathetic ganglia–– Peripheral nervesPeripheral nerves–– ParagangliaParaganglia–– Lymph nodesLymph nodes
![Page 18: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/18.jpg)
Davis, Ann Thorac Surg, 1987Davis, Ann Thorac Surg, 1987
AnteriorAnterior MiddleMiddle PosteriorPosterior
ThymicThymic lesionslesions 30%30% 0%0% 0%0%
LymphomasLymphomas 20%20% 21%21% 20%20%
Germ cell tumorsGerm cell tumors 18%18% 0%0% 0%0%
CarcinomaCarcinoma 13%13% 7%7% 0%0%
CystsCysts 7%7% 60%60% 34%34%
MesenchymalMesenchymal tumorstumors 5%5% 9%9% 9%9%
Endocrine tumorsEndocrine tumors 5%5% 0%0% 2%2%
NeurogenicNeurogenic tumorstumors 0%0% 0%0% 53%53%
MiscellaneousMiscellaneous 2%2% 3%3% 2%2%
MediastinumMediastinumDistribution of lesions (n=400)Distribution of lesions (n=400)
![Page 19: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/19.jpg)
AnteriorAnterior MiddleMiddle PosteriorPosterior
ThymicThymic lesionslesions 30%30% 0%0% 0%0%
LymphomasLymphomas 20%20% 21%21% 20%20%
Germ cell tumorsGerm cell tumors 18%18% 0%0% 0%0%
CarcinomaCarcinoma 13%13% 7%7% 0%0%
CystsCysts 7%7% 60%60% 34%34%
MesenchymalMesenchymal tumorstumors 5%5% 9%9% 9%9%
Endocrine tumorsEndocrine tumors 5%5% 0%0% 2%2%
NeurogenicNeurogenic tumorstumors 0%0% 0%0% 53%53%
MiscellaneousMiscellaneous 2%2% 3%3% 2%2%
MediastinumMediastinumLesions occurring in one compartmentLesions occurring in one compartment
![Page 20: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/20.jpg)
AnteriorAnterior MiddleMiddle PosteriorPosterior
ThymicThymic lesionslesions 30%30% 0%0% 0%0%
LymphomasLymphomas 20%20% 21%21% 20%20%
Germ cell tumorsGerm cell tumors 18%18% 0%0% 0%0%
CarcinomaCarcinoma 13%13% 7%7% 0%0%
CystsCysts 7%7% 60%60% 34%34%
MesenchymalMesenchymal tumorstumors 5%5% 9%9% 9%9%
Endocrine tumorsEndocrine tumors 5%5% 0%0% 2%2%
NeurogenicNeurogenic tumorstumors 0%0% 0%0% 53%53%
MiscellaneousMiscellaneous 2%2% 3%3% 2%2%
MediastinumMediastinumLesions occurring in two compartmentsLesions occurring in two compartments
![Page 21: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/21.jpg)
AnteriorAnterior MiddleMiddle PosteriorPosterior
ThymicThymic lesionslesions 30%30% 0%0% 0%0%
LymphomasLymphomas 20%20% 21%21% 20%20%
Germ cell tumorsGerm cell tumors 18%18% 0%0% 0%0%
CarcinomaCarcinoma 13%13% 7%7% 0%0%
CystsCysts 7%7% 60%60% 34%34%
MesenchymalMesenchymal tumorstumors 5%5% 9%9% 9%9%
Endocrine tumorsEndocrine tumors 5%5% 0%0% 2%2%
NeurogenicNeurogenic tumorstumors 0%0% 0%0% 53%53%
MiscellaneousMiscellaneous 2%2% 3%3% 2%2%
MediastinumMediastinumLesions common to all compartmentsLesions common to all compartments
![Page 22: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/22.jpg)
Davis, Ann Thorac Surg, 1987Davis, Ann Thorac Surg, 1987
AnteriorAnterior MiddleMiddle PosteriorPosterior
ThymicThymic lesionslesions 30%30% 0%0% 0%0%
LymphomasLymphomas 20%20% 21%21% 20%20%
Germ cell tumorsGerm cell tumors 18%18% 0%0% 0%0%
CarcinomaCarcinoma 13%13% 7%7% 0%0%
CystsCysts 7%7% 60%60% 34%34%
MesenchymalMesenchymal tumorstumors 5%5% 9%9% 9%9%
Endocrine tumorsEndocrine tumors 5%5% 0%0% 2%2%
NeurogenicNeurogenic tumorstumors 0%0% 0%0% 53%53%
MiscellaneousMiscellaneous 2%2% 3%3% 2%2%
MediastinumMediastinumMost common lesion in each compartmentMost common lesion in each compartment
![Page 23: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/23.jpg)
MediastinumMediastinumLesions occurring in one compartmentLesions occurring in one compartment
•• ThymicThymic lesionslesions–– AnteriorAnterior
•• Germ cell tumorsGerm cell tumors–– AnteriorAnterior
•• NeurogenicNeurogenic tumorstumors–– PosteriorPosterior
![Page 24: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/24.jpg)
ThymusThymus
•• Thymic lesions dominant mediastinal pathologyThymic lesions dominant mediastinal pathology–– 50% of mediastinal lesions occur in the anterior compartment50% of mediastinal lesions occur in the anterior compartment–– Major organ of the anterior mediastinumMajor organ of the anterior mediastinum
![Page 25: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/25.jpg)
ThymusThymusEmbryologyEmbryology
•• 66thth weekweek–– Primordia arise from 3Primordia arise from 3rdrd
pharyngeal pouches pharyngeal pouches
![Page 26: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/26.jpg)
ThymusThymusEmbryologyEmbryology
•• 66thth weekweek–– Primordia arise from 3Primordia arise from 3rdrd
pharyngeal pouchespharyngeal pouches
•• 88thth weekweek–– Primordia elongatePrimordia elongate–– Fragment during migrationFragment during migration
•• 1414thth week to 16week to 16thth weekweek–– Cortex and medulla completeCortex and medulla complete–– Phenotypic characterizationPhenotypic characterization
![Page 27: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/27.jpg)
ThymusThymusLocationLocation
•• Anterior mediastinumAnterior mediastinum–– Base rests on pericardium and Base rests on pericardium and
great vesselsgreat vessels
![Page 28: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/28.jpg)
ThymusThymusLocation Location
•• Anterior mediastinumAnterior mediastinum–– Base rests on pericardium and Base rests on pericardium and
great vesselsgreat vessels–– Upper poles extend along Upper poles extend along
trachea, attach to trachea, attach to corresponding lobe of thyroid corresponding lobe of thyroid via thyrothymic ligamentvia thyrothymic ligament
![Page 29: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/29.jpg)
•• XX-- or Hor H--shapedshaped•• Fibrous capsuleFibrous capsule•• Wide variation in weightWide variation in weight
–– Mainly related to ageMainly related to age–– Affected by state of Affected by state of
healthhealth–– AverageAverage
•• 15 grams at birth15 grams at birth•• 3030--40 grams at puberty40 grams at puberty•• 1010--15 grams at 60 years 15 grams at 60 years
ThymusThymusGrossGross
![Page 30: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/30.jpg)
LobulesLobules
![Page 31: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/31.jpg)
Starry skyStarry sky
![Page 32: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/32.jpg)
Corticomedullary junctionCorticomedullary junction
![Page 33: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/33.jpg)
Cortex MedullaCortex Medulla
![Page 34: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/34.jpg)
ThymusThymusInvolutionInvolution
•• Decrease in weight and sizeDecrease in weight and size•• AtrophyAtrophy
–– Cortical lymphocytesCortical lymphocytes–– Epithelial elementsEpithelial elements
![Page 35: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/35.jpg)
ThymusThymusInvolutionInvolution
•• Decrease in weight and sizeDecrease in weight and size•• AtrophyAtrophy
–– Cortical lymphocytesCortical lymphocytes–– Epithelial elementsEpithelial elements
•• Cystic Hassall corpusclesCystic Hassall corpuscles
![Page 36: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/36.jpg)
ThymusThymusInvolutionInvolution
•• Decrease in weight and sizeDecrease in weight and size•• AtrophyAtrophy
–– Cortical lymphocytesCortical lymphocytes–– Epithelial elementsEpithelial elements
•• Cystic Hassall corpusclesCystic Hassall corpuscles•• Increasing adipose tissueIncreasing adipose tissue
![Page 37: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/37.jpg)
ThymusThymusInvolutionInvolution
•• Small lymphocytesSmall lymphocytes•• Islands of epithelial cells Islands of epithelial cells
![Page 38: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/38.jpg)
ThymusThymusInvolutionInvolution
•• Small lymphocytesSmall lymphocytes•• Islands of epithelial cellsIslands of epithelial cells
–– SpindleSpindle--shapedshaped–– RosettesRosettes–– Solid nestsSolid nests–– Elongated strandsElongated strands
•• Involution accelerated byInvolution accelerated by–– StressStress–– RadiotherapyRadiotherapy–– ChemotherapyChemotherapy
![Page 39: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/39.jpg)
Tumors of the Thymus and Mediastinum Tumors of the Thymus and Mediastinum WHO ClassificationWHO Classification
•• Epithelial tumorsEpithelial tumors•• Germ cell tumorsGerm cell tumors•• Lymphomas and hematopoietic neoplasmsLymphomas and hematopoietic neoplasms•• Mesenchymal tumorsMesenchymal tumors•• Rare tumorsRare tumors•• MetastasisMetastasis
![Page 40: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/40.jpg)
Tumors of the Thymus and Mediastinum Tumors of the Thymus and Mediastinum WHO ClassificationWHO Classification
•• Epithelial tumorsEpithelial tumors–– ThymomaThymoma–– Thymic carcinomaThymic carcinoma
•• Germ cell tumorsGerm cell tumors•• Lymphomas and hematopoietic neoplasmsLymphomas and hematopoietic neoplasms•• Mesenchymal tumorsMesenchymal tumors•• Rare tumorsRare tumors•• MetastasisMetastasis
![Page 41: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/41.jpg)
Thymoma and Thymic CarcinomaThymoma and Thymic CarcinomaClinical featuresClinical features
•• UncommonUncommon–– Incidence of 1Incidence of 1--5/million population/year5/million population/year–– Incidence has not changed significantly over past three decadesIncidence has not changed significantly over past three decades
•• Wide age range, 7Wide age range, 7--89 years89 years–– Peak 55Peak 55--65 years65 years–– Rare in children and adolescentsRare in children and adolescents
•• No gender biasNo gender bias•• Increased incidence of second cancersIncreased incidence of second cancers
–– Irrespective of histologic type of thymic epithelial tumorIrrespective of histologic type of thymic epithelial tumor
•• Autoimmune diseaseAutoimmune disease–– MG: variable in thymoma (10MG: variable in thymoma (10--80%), rare in thymic carcinoma80%), rare in thymic carcinoma–– Other: common in thymoma, rare in thymic carcinoma Other: common in thymoma, rare in thymic carcinoma
![Page 42: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/42.jpg)
Thymoma and Thymic CarcinomaThymoma and Thymic Carcinoma
•• ThymomasThymomas–– Arise from thymic epithelial cellsArise from thymic epithelial cells–– Exhibit organotypic (thymusExhibit organotypic (thymus--like) architectural featureslike) architectural features
•• Lobular pattern, perivascular spaces, immature TdT/CD1a/CD99+ TLobular pattern, perivascular spaces, immature TdT/CD1a/CD99+ T--cellscells
–– No, mild, or moderate atypia of epithelial cellsNo, mild, or moderate atypia of epithelial cells–– CD5, CD70, CD117 negative epithelial cellsCD5, CD70, CD117 negative epithelial cells–– Not observed in organs other than thymusNot observed in organs other than thymus
•• Arise from heterotopic tissue in head, neck, mediastinum, pleuraArise from heterotopic tissue in head, neck, mediastinum, pleura, lung, lung
–– Absent/low to moderate biologic potentialAbsent/low to moderate biologic potential•• Often curable by surgeryOften curable by surgery•• Variable invasion, metastases rareVariable invasion, metastases rare•• Typically long survival due to indolent clinical courseTypically long survival due to indolent clinical course
![Page 43: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/43.jpg)
•• 33 year old male33 year old male•• Three month history Three month history
–– CoughCough–– Intermittent chest painIntermittent chest pain
![Page 44: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/44.jpg)
![Page 45: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/45.jpg)
ThymomaThymomaGrossGross
•• WellWell--circumscribed, firmcircumscribed, firm•• Up to 34 cmUp to 34 cm•• Fibrous capsuleFibrous capsule•• PinkPink--tan lobulated cut surfacetan lobulated cut surface
![Page 46: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/46.jpg)
ThymomaThymomaGrossGross
•• WellWell--circumscribed, firmcircumscribed, firm•• Up to 34 cmUp to 34 cm•• Fibrous capsuleFibrous capsule•• PinkPink--tan lobulated cut surfacetan lobulated cut surface•• Cystic change commonCystic change common•• Adherence to adjacent Adherence to adjacent
structuresstructures
![Page 47: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/47.jpg)
ThymomaThymoma
•• Biphasic cell populationBiphasic cell population
![Page 48: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/48.jpg)
ThymomaThymoma
•• Biphasic cell populationBiphasic cell population–– Neoplastic epithelial cellsNeoplastic epithelial cells
•• Keratin positiveKeratin positive
![Page 49: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/49.jpg)
ThymomaThymomaHistologyHistology
•• Biphasic cell populationBiphasic cell population–– Neoplastic epithelial cellsNeoplastic epithelial cells
•• Keratin positiveKeratin positive
–– Nonneoplastic lymphocytesNonneoplastic lymphocytes•• CD1a positive TCD1a positive T--cellscells
![Page 50: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/50.jpg)
ThymomaThymoma
•• Biphasic populationBiphasic population•• Organotypic featuresOrganotypic features
–– Lobular patternLobular pattern
![Page 51: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/51.jpg)
ThymomaThymoma
•• Biphasic populationBiphasic population•• Organotypic featuresOrganotypic features
–– Lobular patternLobular pattern–– Perivascular spacesPerivascular spaces
![Page 52: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/52.jpg)
ThymomaThymoma
•• Biphasic populationBiphasic population•• Organotypic featuresOrganotypic features
–– Lobular patternLobular pattern–– Perivascular spacesPerivascular spaces
•• Longitudinal spacesLongitudinal spaces
![Page 53: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/53.jpg)
ThymomaThymoma
•• Biphasic populationBiphasic population•• Organotypic featuresOrganotypic features
–– Lobular patternLobular pattern–– Perivascular spacesPerivascular spaces
•• Longitudinal spacesLongitudinal spaces•• HyalinizedHyalinized
![Page 54: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/54.jpg)
ThymomaThymoma
•• Biphasic populationBiphasic population•• Organotypic featuresOrganotypic features
–– Lobular patternLobular pattern–– Perivascular spacesPerivascular spaces–– Immature TImmature T--cellscells
•• TdT+/CD1a+/CD99+TdT+/CD1a+/CD99+
![Page 55: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/55.jpg)
Thymoma and Thymic CarcinomaThymoma and Thymic Carcinoma
•• Thymic carcinomaThymic carcinoma–– Arise from thymic epithelial cellsArise from thymic epithelial cells–– No or abortive organotypic architectural featuresNo or abortive organotypic architectural features–– ClearClear--cut cytologic atypiacut cytologic atypia–– Frequent CD5, CD70, CD117 expression in epithelial cells, ~ 60%Frequent CD5, CD70, CD117 expression in epithelial cells, ~ 60%–– Resemble carcinomas in other organsResemble carcinomas in other organs–– Malignant Malignant
•• Often unresectableOften unresectable•• Almost always invasive, metastases frequentAlmost always invasive, metastases frequent•• Short survival due to progressive diseaseShort survival due to progressive disease
![Page 56: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/56.jpg)
•• 56 year old male56 year old male•• Two month historyTwo month history
–– Chest painChest pain–– CoughCough
![Page 57: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/57.jpg)
![Page 58: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/58.jpg)
Thymic CarcinomaThymic CarcinomaGrossGross
•• Firm, gritty, grayFirm, gritty, gray--white masswhite mass•• Usually lacks wellUsually lacks well--defined defined
capsule and fibrous bandscapsule and fibrous bands
![Page 59: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/59.jpg)
Thymic CarcinomaThymic CarcinomaGrossGross
•• Firm, gritty, grayFirm, gritty, gray--white masswhite mass•• Usually lacks wellUsually lacks well--defined defined
capsule and fibrous bandscapsule and fibrous bands•• Foci of hemorrhage and Foci of hemorrhage and
necrosisnecrosis
![Page 60: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/60.jpg)
Thymic CarcinomaThymic CarcinomaHistologyHistology
•• Loss of organotypic featuresLoss of organotypic features•• Cytologically malignantCytologically malignant
–– High N:C ratioHigh N:C ratio–– Cellular pleomorphismCellular pleomorphism–– NucleoliNucleoli–– MitosesMitoses–– NecrosisNecrosis
![Page 61: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/61.jpg)
B3 CaB3 Ca
![Page 62: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/62.jpg)
![Page 63: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/63.jpg)
Thymoma and Thymic CarcinomaThymoma and Thymic CarcinomaClassificationClassification
BernatzBernatz19611961
Suster & MoranSuster & Moran19991999
WHOWHO19991999
WHOWHO20042004
Spindle cellSpindle cell WellWell--diff thymomadiff thymoma Type AType A Type AType A
-- ““ ““ Type ABType AB Type ABType AB
Lymphocyte richLymphocyte rich ““ ““ Type B1Type B1 Type B1Type B1
MixedMixed ““ ““ Type B2Type B2 Type B2Type B2
Epithelial richEpithelial rich Atypical thymomaAtypical thymoma Type B3Type B3 Type B3Type B3
-- Thymic carcinomaThymic carcinoma Type CType C Thymic carcinomaThymic carcinoma
![Page 64: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/64.jpg)
Tumors of the Thymus and Mediastinum Tumors of the Thymus and Mediastinum Epithelial tumorsEpithelial tumors
•• Epithelial tumorsEpithelial tumors–– ThymomaThymoma
•• Type A (spindle cell; medullary)Type A (spindle cell; medullary)•• Type AB (mixed)Type AB (mixed)•• Type B1 (lymphocyteType B1 (lymphocyte--rich; lymphocytic; predominantly cortical; organoidrich; lymphocytic; predominantly cortical; organoid•• Type B2 (cortical)Type B2 (cortical)•• Type B3 (epithelial; atypical; squamoid; wellType B3 (epithelial; atypical; squamoid; well--differentiated thymic ca)differentiated thymic ca)•• Rare thymomasRare thymomas
–– Micronodular thymoma with lymphoid stromaMicronodular thymoma with lymphoid stroma–– MetaplasticMetaplastic–– MicroscopicMicroscopic–– SclerosingSclerosing–– LipofibroadenomaLipofibroadenoma
![Page 65: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/65.jpg)
Tumors of the Thymus and Mediastinum Tumors of the Thymus and Mediastinum Epithelial tumorsEpithelial tumors
•• Epithelial tumorsEpithelial tumors–– Thymic carcinomaThymic carcinoma
•• Squamous cell carcinomaSquamous cell carcinoma•• Basaloid carcinomaBasaloid carcinoma•• Mucoepidermoid carcinomaMucoepidermoid carcinoma•• LymphoepithelialLymphoepithelial--like carcinomalike carcinoma•• Sarcomatoid carcinoma (carcinosarcoma)Sarcomatoid carcinoma (carcinosarcoma)•• Clear cell carcinomaClear cell carcinoma•• AdenocarcinomaAdenocarcinoma•• Papillary adenocarcinomaPapillary adenocarcinoma•• Carcinoma with t(15;19) translocationCarcinoma with t(15;19) translocation•• Neuroendocrine carcinomaNeuroendocrine carcinoma
–– Typical and atypical carcinoidTypical and atypical carcinoid–– Large cell neuroendocrine and small cell carcinomaLarge cell neuroendocrine and small cell carcinoma
•• Undifferentiated carcinomaUndifferentiated carcinoma•• Combined thymic epithelial tumorsCombined thymic epithelial tumors
![Page 66: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/66.jpg)
Thymoma and Thymic CarcinomaThymoma and Thymic CarcinomaTermsTerms
•• EncapsulatedEncapsulated–– Completely surrounded by a fibrous capsuleCompletely surrounded by a fibrous capsule
•• Minimally or microscopically invasiveMinimally or microscopically invasive–– Invasive through the capsule to involve pericapsular tissueInvasive through the capsule to involve pericapsular tissue
•• Usually identified only after microscopic examinationUsually identified only after microscopic examination•• Generally appears encapsulated to surgeonGenerally appears encapsulated to surgeon
•• Widely invasiveWidely invasive–– Spread by direct extension into adjacent structuresSpread by direct extension into adjacent structures
•• ImplantsImplants–– Nodules separate from main mass on pericardium or pleuraNodules separate from main mass on pericardium or pleura
•• Lymph node metastasesLymph node metastases–– Nodes separate from main mass, excludes direct extension into noNodes separate from main mass, excludes direct extension into nodede
•• With distant metastasesWith distant metastases–– Most commonly to lung, liver, skeletal systemMost commonly to lung, liver, skeletal system
![Page 67: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/67.jpg)
Capsular InvasionCapsular Invasion
•• Evaluation of capsule is Evaluation of capsule is essentialessential–– Ink marginsInk margins
•• Adherence to adjacent Adherence to adjacent structuresstructures–– CommonCommon–– DoesnDoesn’’t always indicate true t always indicate true
invasioninvasion
![Page 68: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/68.jpg)
![Page 69: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/69.jpg)
![Page 70: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/70.jpg)
![Page 71: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/71.jpg)
Tumor 400x InvolutionTumor 400x Involution
![Page 72: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/72.jpg)
Thymoma and Thymic CarcinomaThymoma and Thymic CarcinomaPrinciples of classificationPrinciples of classification
•• ThymomaThymoma–– Two major typesTwo major types
•• Uniformly bland spindle or oval epithelial cells Uniformly bland spindle or oval epithelial cells –– Type AType A•• Predominantly round or polygonal epithelial cells Predominantly round or polygonal epithelial cells –– Type BType B
–– Type B subdivided by extent of lymphoid infiltrates and cellularType B subdivided by extent of lymphoid infiltrates and cellularatypiaatypia•• B1 B1 –– lymphocyte richlymphocyte rich•• B2 and B3 B2 and B3 –– epithelial cell richepithelial cell rich
–– Type A plus B1Type A plus B1--like, and rarely B2like, and rarely B2--like, are designated ABlike, are designated AB
•• Thymic carcinomaThymic carcinoma–– Thymic carcinomas are termed according to differentiationThymic carcinomas are termed according to differentiation–– Combined thymomas are termed by WHO histology and %Combined thymomas are termed by WHO histology and %–– ““Malignant thymomaMalignant thymoma”” is discouragedis discouraged
![Page 73: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/73.jpg)
ThymomaThymomaType AType A
•• Lymphocyte poorLymphocyte poor•• Solid sheetsSolid sheets
–– No patternNo pattern
![Page 74: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/74.jpg)
ThymomaThymomaType AType A
•• Lymphocyte poorLymphocyte poor•• Solid sheetsSolid sheets
–– No pattern or storiformNo pattern or storiform
![Page 75: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/75.jpg)
ThymomaThymomaType AType A
•• Lymphocyte poorLymphocyte poor•• Solid sheetsSolid sheets
–– No pattern or storiformNo pattern or storiform–– CystsCysts–– Lobules and bands less Lobules and bands less
conspicuous than other typesconspicuous than other types
![Page 76: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/76.jpg)
ThymomaThymomaType AType A
•• Lymphocyte poorLymphocyte poor•• Solid sheetsSolid sheets
–– No pattern or storiformNo pattern or storiform–– CystsCysts–– Lobules and bands less Lobules and bands less
conspicuous than other typesconspicuous than other types
•• Spindle or oval epithelial cellsSpindle or oval epithelial cells–– Reticulin fibers surround cellsReticulin fibers surround cells
![Page 77: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/77.jpg)
ThymomaThymomaType AType A
•• Lymphocyte poorLymphocyte poor•• Solid sheetsSolid sheets
–– No pattern or storiformNo pattern or storiform–– CystsCysts–– Lobules and bands less Lobules and bands less
conspicuous than other typesconspicuous than other types
•• Spindle or oval epithelial cellsSpindle or oval epithelial cells–– Reticulin fibers surround cellsReticulin fibers surround cells
•• Bland nucleiBland nuclei–– Dispersed chromatinDispersed chromatin–– Inconspicuous nucleoliInconspicuous nucleoli
![Page 78: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/78.jpg)
ThymomaThymomaType ABType AB
•• Mixture of Type A and Type BMixture of Type A and Type B–– Discrete separate nodules orDiscrete separate nodules or
![Page 79: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/79.jpg)
ThymomaThymomaType ABType AB
•• Mixture of Type A and Type BMixture of Type A and Type B–– Discrete separate nodules orDiscrete separate nodules or–– Intermixed A and BIntermixed A and B
![Page 80: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/80.jpg)
ThymomaThymomaType ABType AB
•• Mixture of Type A and Type BMixture of Type A and Type B–– Discrete separate nodules orDiscrete separate nodules or–– Intermixed A and BIntermixed A and B
•• Type B epithelial cells Type B epithelial cells –– Small polygonalSmall polygonal–– Dispersed chromatinDispersed chromatin–– Inconspicuous nucleoliInconspicuous nucleoli
![Page 81: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/81.jpg)
ThymomaThymomaType ABType AB
•• Mixture of Type A and Type BMixture of Type A and Type B–– Discrete separate nodules orDiscrete separate nodules or–– Intermixed A and BIntermixed A and B
•• Type B epithelial cells Type B epithelial cells –– Small polygonalSmall polygonal–– Dispersed chromatinDispersed chromatin–– Inconspicuous nucleoliInconspicuous nucleoli
•• B areasB areas–– Medullary differentiation rareMedullary differentiation rare–– Hassall corpuscles absentHassall corpuscles absent–– Reticulin around B nodulesReticulin around B nodules
•• Not around individual cellsNot around individual cells
![Page 82: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/82.jpg)
ThymomaThymomaType B1Type B1
•• Resembles cortexResembles cortex
![Page 83: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/83.jpg)
ThymomaThymomaType B1Type B1
•• Resembles cortexResembles cortex•• Scant small epithelial cellsScant small epithelial cells
–– Pale nucleiPale nuclei–– Small nucleoliSmall nucleoli
![Page 84: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/84.jpg)
ThymomaThymomaType B1Type B1
•• Resembles cortexResembles cortex•• Scant small epithelial cellsScant small epithelial cells
–– Pale nucleiPale nuclei–– Small nucleoliSmall nucleoli
•• Dispersed epithelial cellsDispersed epithelial cells–– Do not from groupingsDo not from groupings
![Page 85: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/85.jpg)
ThymomaThymomaType B1Type B1
•• Resembles cortexResembles cortex•• Scant small epithelial cellsScant small epithelial cells
–– Pale nucleiPale nuclei–– Small nucleoliSmall nucleoli
•• Dispersed epithelial cellsDispersed epithelial cells–– Do not from groupingsDo not from groupings
•• Medullary differentiation always present
Medullary differentiation always present
![Page 86: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/86.jpg)
ThymomaThymomaType B1Type B1
•• Resembles cortexResembles cortex•• Dispersed epithelial cellsDispersed epithelial cells
–– Do not from groupingsDo not from groupings
•• Scant small epithelial cellsScant small epithelial cells–– Pale nucleiPale nuclei–– Small nucleoliSmall nucleoli
•• Medullary differentiation always present
Medullary differentiation
always present
•• Hassall corpuscles may be present Hassall corpuscles may be present
![Page 87: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/87.jpg)
ThymomaThymomaType B2Type B2
•• Large course lobulesLarge course lobules–– Separated by delicate septaSeparated by delicate septa
![Page 88: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/88.jpg)
ThymomaThymomaType B2Type B2
•• Large course lobulesLarge course lobules–– Separated by delicate septaSeparated by delicate septa
•• Large polygonal epithelial cellsLarge polygonal epithelial cells–– Open chromatinOpen chromatin–– Prominent nucleoliProminent nucleoli
![Page 89: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/89.jpg)
ThymomaThymomaType B2Type B2
•• Large course lobulesLarge course lobules–– Separated by delicate septaSeparated by delicate septa
•• Large polygonal epithelial cellsLarge polygonal epithelial cells–– Open chromatinOpen chromatin–– Prominent nucleoliProminent nucleoli
•• Medullary differentiation absent or inconspicuous
Medullary differentiation absent or inconspicuous
•• Abortive Hassall in 25%Abortive Hassall in 25%–– Typical Hassall rareTypical Hassall rare
•• B3 occurs in B2B3 occurs in B2–– 1717--29% of cases29% of cases–– Designate B2/B3Designate B2/B3
![Page 90: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/90.jpg)
ThymomaThymomaType B3Type B3
•• Lobules with thick septaLobules with thick septa
![Page 91: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/91.jpg)
ThymomaThymomaType B3Type B3
•• Lobules with thick septaLobules with thick septa•• Paucity of lymphoctyesPaucity of lymphoctyes
–– Results in sheetResults in sheet--like growthlike growth
![Page 92: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/92.jpg)
ThymomaThymomaType B3Type B3
•• Lobules with thick septaLobules with thick septa•• Paucity of lymphoctyesPaucity of lymphoctyes
–– Results in sheetResults in sheet--like growthlike growth–– Solid or epidermoid patternSolid or epidermoid pattern
•• No intercellular bridgesNo intercellular bridges
![Page 93: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/93.jpg)
ThymomaThymomaType B3Type B3
•• Lobules with thick septaLobules with thick septa•• Paucity of lymphoctyesPaucity of lymphoctyes
–– Results in sheetResults in sheet--like growthlike growth–– Solid or epidermoid patternSolid or epidermoid pattern
•• No intercellular bridgesNo intercellular bridges
•• MediumMedium--size epithelial cellssize epithelial cells–– Small nucleoliSmall nucleoli–– Often grooved nucleiOften grooved nuclei
![Page 94: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/94.jpg)
ThymomaThymomaType B3Type B3
•• Lobules with thick septaLobules with thick septa•• Paucity of lymphoctyesPaucity of lymphoctyes
–– Results in sheetResults in sheet--like growthlike growth–– Solid or epidermoid patternSolid or epidermoid pattern
•• No intercellular bridgesNo intercellular bridges
•• MediumMedium--size epithelial cellssize epithelial cells–– Small nucleoliSmall nucleoli–– Often grooved nucleiOften grooved nuclei
•• Perivascular palisadingPerivascular palisading
![Page 95: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/95.jpg)
ThymomaThymomaType B3Type B3
•• Lobules with thick septaLobules with thick septa•• Paucity of lymphoctyesPaucity of lymphoctyes
–– Results in sheetResults in sheet--like growthlike growth–– Solid or epidermoid patternSolid or epidermoid pattern
•• No intercellular bridgesNo intercellular bridges
•• MediumMedium--size epithelial cellssize epithelial cells–– Small nucleoliSmall nucleoli–– Often grooved nucleiOften grooved nuclei
•• Perivascular palisadingPerivascular palisading•• Foci of keratinizationFoci of keratinization
–– Mimicking Hassall corpusclesMimicking Hassall corpuscles
•• Medullary differentiation usually absent
Medullary differentiation usually absent
![Page 96: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/96.jpg)
A B3 A B3
![Page 97: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/97.jpg)
B1 B2B1 B2B3 CaB3 Ca
![Page 98: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/98.jpg)
B1 B2B1 B2
![Page 99: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/99.jpg)
Thymoma and Thymic CarcinomaThymoma and Thymic CarcinomaPrevalence of subtypesPrevalence of subtypes
•• AB AB –– 2020--35%35%•• B2 B2 –– 2020--35%35%•• A A –– 55--10%10%•• B1 B1 –– 55--10%10%•• Thymic carcinoma 10Thymic carcinoma 10--25%25%
![Page 100: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/100.jpg)
Thymoma and Thymic CarcinomaThymoma and Thymic CarcinomaSpectrum of MalignancySpectrum of Malignancy
•• ThymomaThymoma–– Type AType A–– Type ABType AB–– Type B1Type B1–– Type B2Type B2–– Type B3Type B3
•• Thymic carcinoidsThymic carcinoids•• Thymic carcinomaThymic carcinoma
–– Squamous cell, basaloid, mucoepidermoidSquamous cell, basaloid, mucoepidermoid–– Other subtypesOther subtypes
•• Small cell and large cell neuroendocrineSmall cell and large cell neuroendocrine
![Page 101: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/101.jpg)
Thymoma and Thymic CarcinomaThymoma and Thymic CarcinomaPrognosisPrognosis
•• Most important prognostic factorsMost important prognostic factors–– Tumor stageTumor stage
•• MasaokaMasaoka stage is the most important and statistically most significant stage is the most important and statistically most significant independent prognostic indicator of survival in most studiesindependent prognostic indicator of survival in most studies
–– WHO histologic typeWHO histologic type–– Completeness of resectionCompleteness of resection
![Page 102: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/102.jpg)
Thymoma and Thymic CarcinomaThymoma and Thymic CarcinomaPrognosisPrognosis
HistologyHistology StageStage Biologic PotentialBiologic Potential
A, AB, B1A, AB, B1 l and lll and llllllll
None/very lowNone/very lowLowLow
B2, B3B2, B3 llll and lllll and lll
LowLowModerateModerate
Squam, basaloid, Squam, basaloid, mucoep, carcinoidmucoep, carcinoid
l and lll and llllllll
ModerateModerateHighHigh
Other histologyOther histology AnyAny HighHigh
![Page 103: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/103.jpg)
StagingStagingTNM TNM
•• T1 T1 –– tumor completely encapsulatedtumor completely encapsulated•• T2 T2 –– tumor invades pericapsular connective tissuetumor invades pericapsular connective tissue•• T3 T3 –– tumor invades into neighboring structures, such as tumor invades into neighboring structures, such as
pericardium, mediastinal pleura, thoracic wall, great vessels pericardium, mediastinal pleura, thoracic wall, great vessels and lungand lung
•• T4 T4 –– tumor with pleural or pericardial disseminationtumor with pleural or pericardial dissemination
•• Currently no authorized TNM system for thymic epithelial or Currently no authorized TNM system for thymic epithelial or neuroendocrine tumorsneuroendocrine tumors
![Page 104: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/104.jpg)
StagingStagingModified Masaoka Modified Masaoka
•• Stage 1:Stage 1: intact capsule or growth within capsuleintact capsule or growth within capsule•• Stage 2a:Stage 2a: microscopic invasion through capsulemicroscopic invasion through capsule
2b:2b: gross and microscopic invasiongross and microscopic invasion•• Stage 3:Stage 3: invasion into surrounding structuresinvasion into surrounding structures•• Stage 4a:Stage 4a: pleural or pericardial disseminationpleural or pericardial dissemination
4b:4b: lymphatic or hematogenous metastaseslymphatic or hematogenous metastases
![Page 105: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/105.jpg)
Thymoma and Thymic CarcinomaThymoma and Thymic CarcinomaDiagnosisDiagnosis
•• ThymomaThymoma–– EncapsulatedEncapsulated–– Invasive (term malignant thymoma is discourage)Invasive (term malignant thymoma is discourage)
•• Surgical pathology reportSurgical pathology report–– Correct diagnosisCorrect diagnosis
•• Up to 20% in some studies incorrectly diagnosedUp to 20% in some studies incorrectly diagnosed
–– Assessment of surgical marginsAssessment of surgical margins•• Requires inkingRequires inking
–– Determination of invasivenessDetermination of invasiveness•• Multiple sections through capsuleMultiple sections through capsule
![Page 106: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/106.jpg)
Thymoma and Thymic CarcinomaThymoma and Thymic CarcinomaDiagnosisDiagnosis
•• Thymic carcinomaThymic carcinoma–– Separation from metastatic carcinoma may be difficultSeparation from metastatic carcinoma may be difficult
•• Lung, thyroid, breast, prostate are most commonLung, thyroid, breast, prostate are most common
–– May only be able to suggest or favor diagnosis May only be able to suggest or favor diagnosis •• Clinical history and radiologic studies are essentialClinical history and radiologic studies are essential
![Page 107: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/107.jpg)
Thymoma and Thymic CarcinomaThymoma and Thymic CarcinomaDiagnosisDiagnosis
TumorTumor Thymic primaryThymic primary Lung or head/neckLung or head/neck
Squamous, basaloid, Squamous, basaloid, lympholympho--epi caepi ca Lobular growth 70%Lobular growth 70% Lobular growth rareLobular growth rare
Perivascular spaces 50%Perivascular spaces 50% Perivascular spaces rarePerivascular spaces rare
CD5 50%CD5 50% CD5 not expressedCD5 not expressed
CD70 50%CD70 50% CD70 not expressedCD70 not expressed
CD117 40CD117 40--100%100% CD117 not expressedCD117 not expressed
NE carcinomaNE carcinoma TTFTTF--1 absent1 absent TTFTTF--1 frequent (lung)1 frequent (lung)
![Page 108: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/108.jpg)
Tumors of the Thymus and Mediastinum Tumors of the Thymus and Mediastinum WHO ClassificationWHO Classification
•• Epithelial tumorsEpithelial tumors•• Germ cell tumorsGerm cell tumors
–– 2003 WHO Classification of Germ Cell Tumors2003 WHO Classification of Germ Cell Tumors•• TeratomaTeratoma•• SeminomaSeminoma
•• Lymphomas and hematopoietic neoplasmsLymphomas and hematopoietic neoplasms•• Mesenchymal tumorsMesenchymal tumors•• Rare tumorsRare tumors•• MetastasisMetastasis
![Page 109: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/109.jpg)
Tumors of the Thymus and Mediastinum Tumors of the Thymus and Mediastinum WHO ClassificationWHO Classification
•• Epithelial tumorsEpithelial tumors•• Germ cell tumorsGerm cell tumors•• Lymphomas and hematopoietic neoplasmsLymphomas and hematopoietic neoplasms
–– 2001 WHO Classification of Hematopoietic and Lymphoid Tumors2001 WHO Classification of Hematopoietic and Lymphoid Tumors•• NS Classical HLNS Classical HL•• PMLBPMLB--CLCL•• TT--lymphoblastic leukemia/lymphomalymphoblastic leukemia/lymphoma•• MALT lymphomaMALT lymphoma
•• Mesenchymal tumorsMesenchymal tumors•• Rare tumorsRare tumors•• MetastasisMetastasis
![Page 110: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/110.jpg)
Tumors of the Thymus and Mediastinum Tumors of the Thymus and Mediastinum WHO ClassificationWHO Classification
•• Epithelial tumorsEpithelial tumors•• Germ cell tumorsGerm cell tumors•• Lymphomas and hematopoietic neoplasmsLymphomas and hematopoietic neoplasms•• Mesenchymal tumorsMesenchymal tumors
–– 2000 WHO Classification of Nervous System2000 WHO Classification of Nervous System•• SchwannomaSchwannoma
–– 2002 WHO Classification of Soft Tissue and Bone2002 WHO Classification of Soft Tissue and Bone•• ThymolipomaThymolipoma
•• Rare tumorsRare tumors•• MetastasisMetastasis
![Page 111: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/111.jpg)
Tumors of the Thymus and Mediastinum Tumors of the Thymus and Mediastinum WHO ClassificationWHO Classification
•• Epithelial tumorsEpithelial tumors•• Germ cell tumorsGerm cell tumors•• Lymphomas and hematopoietic neoplasmsLymphomas and hematopoietic neoplasms•• Mesenchymal tumorsMesenchymal tumors•• Rare tumorsRare tumors
–– Ectopic tumors of the thymusEctopic tumors of the thymus•• Ectopic thyroid tumorsEctopic thyroid tumors•• Ectopic parathyroid tumorsEctopic parathyroid tumors
•• MetastasisMetastasis
![Page 112: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/112.jpg)
Rare TumorsRare TumorsEctopic tumorsEctopic tumors
•• Uncommon, benign or Uncommon, benign or malignantmalignant
•• Anterior or posterior Anterior or posterior compartmentcompartment
•• ThyroidThyroid–– Extension from neck or Extension from neck or
ectopic tissueectopic tissue
•• ParathyroidParathyroid–– Found adjacent to or within Found adjacent to or within
thymusthymus
![Page 113: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/113.jpg)
Tumors of the Thymus and Mediastinum Tumors of the Thymus and Mediastinum WHO ClassificationWHO Classification
•• Epithelial tumorsEpithelial tumors•• Germ cell tumorsGerm cell tumors•• Lymphomas and hematopoietic neoplasmsLymphomas and hematopoietic neoplasms•• Mesenchymal tumorsMesenchymal tumors•• Rare tumorsRare tumors•• MetastasisMetastasis
–– Thymus and anterior (middle) mediastinumThymus and anterior (middle) mediastinum•• Lung, thyroid, breast, prostate are most commonLung, thyroid, breast, prostate are most common
![Page 114: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/114.jpg)
•• Three compartmentsThree compartments•• Mediastinal lesionsMediastinal lesions
–– 50% of lesions50% of lesions•• Anterior compartmentAnterior compartment
–– ThymicThymic lesions dominatelesions dominate–– Organization by compartmentOrganization by compartment
Mediastinal PathologyMediastinal PathologySummarySummary
![Page 115: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/115.jpg)
![Page 116: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/116.jpg)
AnteriorAnterior MiddleMiddle PosteriorPosterior
ThymicThymic lesionslesions 30%30% 0%0% 0%0%
LymphomasLymphomas 20%20% 21%21% 10%10%
Germ cell tumorsGerm cell tumors 18%18% 0%0% 0%0%
CarcinomaCarcinoma 13%13% 7%7% 0%0%
CystsCysts 7%7% 60%60% 24%24%
MesenchymalMesenchymal tumorstumors 5%5% 9%9% 9%9%
Endocrine tumorsEndocrine tumors 5%5% 0%0% 2%2%
NeurogenicNeurogenic tumorstumors 0%0% 0%0% 53%53%
MiscellaneousMiscellaneous 2%2% 3%3% 2%2%
MediastinumMediastinumLesions occurring in one compartmentLesions occurring in one compartment
![Page 117: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/117.jpg)
AnteriorAnterior MiddleMiddle PosteriorPosterior
ThymicThymic lesionslesions 30%30% 0%0% 0%0%
LymphomasLymphomas 20%20% 21%21% 10%10%
Germ cell tumorsGerm cell tumors 18%18% 0%0% 0%0%
CarcinomaCarcinoma 13%13% 7%7% 0%0%
CystsCysts 7%7% 60%60% 24%24%
MesenchymalMesenchymal tumorstumors 5%5% 9%9% 9%9%
Endocrine tumorsEndocrine tumors 5%5% 0%0% 2%2%
NeurogenicNeurogenic tumorstumors 0%0% 0%0% 53%53%
MiscellaneousMiscellaneous 2%2% 3%3% 2%2%
MediastinumMediastinumLesions occurring in two compartmentsLesions occurring in two compartments
![Page 118: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/118.jpg)
AnteriorAnterior MiddleMiddle PosteriorPosterior
ThymicThymic lesionslesions 30%30% 0%0% 0%0%
LymphomasLymphomas 20%20% 21%21% 10%10%
Germ cell tumorsGerm cell tumors 18%18% 0%0% 0%0%
CarcinomaCarcinoma 13%13% 7%7% 0%0%
CystsCysts 7%7% 60%60% 24%24%
MesenchymalMesenchymal tumorstumors 5%5% 9%9% 9%9%
Endocrine tumorsEndocrine tumors 5%5% 0%0% 2%2%
NeurogenicNeurogenic tumorstumors 0%0% 0%0% 53%53%
MiscellaneousMiscellaneous 2%2% 3%3% 2%2%
MediastinumMediastinumLesions occurring in all compartmentsLesions occurring in all compartments
![Page 119: Mediastinal Pathology Compartmental Approach](https://reader034.vdocument.in/reader034/viewer/2022042700/55496828b4c90595518b4b66/html5/thumbnails/119.jpg)
AnteriorAnterior MiddleMiddle PosteriorPosterior
ThymicThymic lesionslesions 30%30% 0%0% 0%0%
LymphomasLymphomas 20%20% 21%21% 10%10%
Germ cell tumorsGerm cell tumors 18%18% 0%0% 0%0%
CarcinomaCarcinoma 13%13% 7%7% 0%0%
CystsCysts 7%7% 60%60% 24%24%
MesenchymalMesenchymal tumorstumors 5%5% 9%9% 9%9%
Endocrine tumorsEndocrine tumors 5%5% 0%0% 2%2%
NeurogenicNeurogenic tumorstumors 0%0% 0%0% 53%53%
MiscellaneousMiscellaneous 2%2% 3%3% 2%2%
MediastinumMediastinumMost common lesionMost common lesion