Acquired cystic transformation of the rete testis secondary to renal failure.

The histologic study of testicular specimens from 218 consecutive autopsies revealed a cystic transformation of the rete testis in 26 men. Serial sections of the testes, epididymides, and spermatic cords of these men were studied by light microscopy. In 15 cases, the rete testis dilation was caused by obstruction of the epididymis. In five cases, the dilation was due to obstruction of the intratesticular excretory ducts caused by varicocele. In the remaining six men, no evidence of obstructive processes was found. These six patients had been diagnosed with renal failure and underwent hemodialysis. The rete testis in these men showed dilated channels lined by a high columnar or pseudostratified epithelium. They contained spermatozoa, with a proteinaceous material and calcium oxalate crystals. The ductuli efferents showed eosinophilic granules in their epithelial cells and their lumen contained spermatids, spermatozoa, cell remnants, calcium oxalate crystals, and multinucleate giant cells. These rete testis lesions are similar to those previously reported in the kidney of hemodialyzed patients.