Pathology of germ cell tumors of the testis.

BACKGROUND An increasing incidence of testis tumors has been noted over the second half of the 20th century. Congenital malformation of the male genitalia, prenatal risk factors, nonspecific and specific exposures in adulthood, and male infertility have all been associated with the etiology of germ cell tumors. METHODS The histologic classification, pathology, and current concepts of testicular germ cell tumors are reviewed. RESULTS Germ cell tumors occur at all ages. The tumors are identified as pure form (those of one histologic type) and mixed form (more than one histologic type). Over half of germ cell tumors consist of more than one cell type, requiring appropriate sampling for the correct diagnosis and correlation with the serum tumor markers. Burned-out germ cell tumors may occur in patients with metastatic disease with no gross evidence of a testicular tumor. CONCLUSIONS Appropriate management of testis tumors relies on accurate pathology and classification of these tumors.