Adenofibroma of the rete testis. A case report with electron microscopy findings.

The light and electron microscopic characteristics of an adenofibroma of the rete testis in a 51-year-old man are described. The tumor was 5.5 cm in greatest diameter and situated in the anterior superior portion of the right testis. It was composed mainly of mesenchymal and secondary epithelial proliferation. Long slit-like spaces and short tubules lined by a layer of epithelial cells were seen in the mesenchymal tissue. The epithelium was histochemically and ultrastructurally similar to that of the rete testis, and the tumor was considered to be of rete testis origin.