Human epithelial thymic tumours: heterogeneity in immunostaining of epithelial cell markers and thymic hormones.
Different hormones (thymulin, thymosin alpha 1, vasopressin), antigenic markers of cortical and subcapsular/medullary thymic areas and tumour associated antigens were studied on paraffin or frozen section and cultures of human epithelial thymic tumours ('thymomas'). Thymulin, thymosin alpha 1 and for the first time vasopressin are found in most tumours. The epithelial cells of five 'thymomas' had markers of both cortical (TE3) and subcapsular/medullary thymic regions (A2B5 and/or TE4 and/or anti-p19). Leu-7, a marker of subcapsular epithelial cells was positive only in two tumours. The histological classification into cortical and medullary tumours does not correspond to our immunofluorescence results. The presence of these markers does not support the theory of different embryologic origin of the cortical and subcapsular/medullary epithelial cells. Transferrin receptors were detected on only some epithelial cells of thymic 'carcinomas'. Adenocarcinoma related antigen and carcino embryonic antigen only stained a few epithelial cells of all the tumours. There is no expected correlation between the presence of epidermal growth factor receptors on cell membranes and the number of proliferative cells stained by the anti-Ki67 antibodies. Immunostainings were heterogeneous according to the epithelial thymic tumours, independent of histological classification and not yet useful for prognosis.
Laboratoire d'Histologie, UFR Alexis Carrel, Lyon, France.
F
F
Giraud
N
N
Fabien
C
C
Auger
C
C
Girod
R
R
Loire
J C
JC
Monier
D000328:Adult; D000368:Aged; D000951:Antigens, Neoplasm / Q000032:analysis*; D066246:ErbB Receptors / Q000032:analysis; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D013194:Staining and Labeling; D013951:Thymus Hormones / Q000032:analysis*; D013953:Thymus Neoplasms / Q000032:analysis* / Q000276:immunology; D014407:Tumor Cells, Cultured; D014667:Vasopressins / Q000032:analysis
D000951:Antigens, Neoplasm; D013951:Thymus Hormones; D014667:Vasopressins; D066246:ErbB Receptors