Immunohistochemical evidence for mesothelial origin of paratesticular adenomatoid tumour.
OBJECTIVE
To investigate the histogenesis of paratesticular adenomatoid tumour by use of immunohistochemical markers for a variety of carcinomas and mesothelioma.


RESULTS
Immunohistochemical staining of sections from 12 cases of paratesticular adenomatoid tumour was undertaken using primary antibodies to antigens expressed by benign epithelial cells and carcinoma (cytokeratin AE1/AE3, cytokeratin 34ssE12, epithelial membrane antigen, MOC-31, Ber-EP4, CEA, B72.3, LEA.135, Leu M1), stromal and vascular markers (vimentin, CD34, factor VIII), and mesothelioma-associated antigens (thrombomodulin, HBME-1, OC 125) and p53 protein. There was absence of immunohistochemical expression of epithelial/carcinoma markers MOC-31, Ber-EP4, CEA, B72.3, LEA.135, Leu M1 and to factor VIII and CD34. All tumours expressed cytokeratin AE1/AE3, epithelial membrane antigen and vimentin, with weak expression of cytokeratin 34ssE12 in 25% of tumours. Each tumour showed expression of thrombomodulin, HBME-1 and OC 125 in a membranous distribution. p53 protein expression was not detected.


CONCLUSIONS
The immunohistochemical profile of paratesticular adenomatoid tumour is strongly supportive of a mesothelial cell origin.
Delahunt
B
B
Departments of Pathology, Wellington School of Medicine, University of Otago, New Zealand. bd@wnmeds.ac.nz
Eble
J N
JN
King
D
D
Bethwaite
P B
PB
Nacey
J N
JN
Thornton
A
A
D018254:Adenomatoid Tumor / Q000378:metabolism / Q000473:pathology*; D014408:Biomarkers, Tumor / Q000032:analysis; D018394:CA-125 Antigen / Q000032:analysis; D006801:Humans; D007150:Immunohistochemistry; D007633:Keratins / Q000032:analysis; D008297:Male; D008654:Mesothelioma / Q000378:metabolism / Q000473:pathology*; D018396:Mucin-1 / Q000032:analysis; D013736:Testicular Neoplasms / Q000378:metabolism / Q000473:pathology*; D013737:Testis / Q000737:chemistry / Q000473:pathology; D018180:Thrombomodulin / Q000032:analysis; D014746:Vimentin / Q000032:analysis
D014408:Biomarkers, Tumor; D018394:CA-125 Antigen; D018396:Mucin-1; D018180:Thrombomodulin; D014746:Vimentin; D007633:Keratins