Benign hemangioendothelioma of the testis: case report with electron microscopic documentation and review of the literature.

Tumors of non-specialized gonadal mesenchyme have been reported only rarely. An intratesticular benign hemangioendothelioma from a 26-year-old man presented a diagnostic challenge due to the infrequency of well-defined vascular lumens. Electron microscopy was helpful in defining the vascular nature of the tumor. In spite of the cellularity of the neoplasm, there has been no recurrence or metastasis over a two and one-half year follow-up period. The histological features are compared with those of previously reported cases.