RETROGRESSION IN TESTICULAR SEMINOMA WITH VIABLE METASTASES.

Stages in the retrogression of testicular seminoma are described. Eosinophilic necrosis fringed by palisaded histiocytes may be followed by fibrous replacement. Oxidation of unsaturated phospholipids in necrotic tumour may lead to deposition of lipofuscin around the lesion. Search for partially or completely scarred lesions is essential before contemplating a diagnosis of primary retroperitoneal seminoma. Retrogressed seminoma can often be distinguished from retrogressed teratoid tumours. Apparently paradoxical teratoid metastases in association with a testicular seminoma are explained on the basis of misinterpreted retrogressed teratoid tumours in association with the seminoma. Inguinal node metastases from testicular seminoma may be the result of abnormal lymphatic drainage following previous scrotal operations, testicular torsion etc.