Anaplastic seminoma of the testis: ultrastructural analysis of three cases.

Three anaplastic seminomas of the testis were examined by transmission electron microscopy, and the ultrastructural features are described for comparison with those reported in other seminomas and related neoplasms. It is concluded that anaplastic seminomas are similar ultrastructurally to classic testicular seminomas, extragondal seminomas, and ovarian dysgerminomas, all of which are less differentiated than spermatocytic seminomas.