[Case studies of the histological characterization of primary tumors of the testis].

One hundred-ninety nine cases of testicular tumours, of which 189 (94,9%) germ cell tumours, have been studied by histological methods. Seminoma with its two subtypes (anaplastic and spermatocytic) is the most frequent tumour (110 cases i.e. 55,2%), followed by embryonal carcinoma (30 cases: 15,3%), teratocarcinoma (25 cases: 13,2%), teratoma (12 cases: 6,3%) and choriocarcinoma (5 cases: 2,6%). Tumours showing more than one histologic pattern are frequent. The distinctive histologic features have studied, with emphasis of those useful for diagnostic and prognostic purposes. The ages mostly involved by various tumours are stressed. The rarest tumours are briefly described. Histologic data suggest that germinal tumours are originated by the same primordial germ cell which is able to develop various degrees of differentiation. Histologic and histogenetic features of limphomas and tumours of specialized gonadal stroma are also discussed.