Papillary adenocarcinoma of rete testis. Autopsy findings, histochemistry, immunohistochemistry, ultrastructure, and clinical correlations.

Adenocarcinoma of the rete testis is a rare neoplasm that usually occurs in men after the age of 60 and carries a variable prognosis. We report an occurrence of this tumor in a 91-year-old man who had been treated for 2 years for an hydrocele. At the time of diagnosis, metastases were not evident; and the patient was treated with local radiotherapy. The diagnosis of papillary adenocarcinoma of the rete testis was made on the basis of: (a) a transition from normal rete testis to atypical and neoplastic rete epithelium; (b) exclusion of primary germinal and nongerminal testicular tumors and spread from distant sources; and (c) electron-microscopic findings, histochemical and immunological studies, and autopsy findings supporting the diagnosis. This is the first reported case of adenocarcinoma of the rete testis that includes documentation of the tumor's metastatic pattern.