Lymph node metastases with PAS-positive tumor cells and massive epithelioid granulomatous reaction as diagnostic clue to occult seminoma.

Two cases of occult seminoma were observed which showed left-sided lymph node metastases without clinically demonstrable testicular tumors. The peculiar histology of the lymph node metastases, namely PAS-positive tumor cells with clear cytoplasm together with a granulomatous stromal reaction, was highly suggestive of seminoma. Despite lack of testicular enlargement in both cases, a left-sided orchiectomy was done. Histologically, intratubular seminomas were found which confirmed the original diagnostic suspicions derived from the morphology of the lymph node metastases. It is concluded, therefore, that in the case of lymph node metastases with the above-mentioned structure, occult seminoma should always be taken into consideration. Because of the modern beneficial therapeutic implications, detection of occult seminoma is very important.