Cystic transformation of the rete testis.

In a review of the testicular and epididymal specimens obtained from autopsies (1,798 men) or surgery (518 men), cystic transformation of the rete testis (CTRT) was found in 20 autopsies and 18 surgical specimens. When both testes were studied (autopsies), the lesion was bilateral. Ultrasonography revealed a widened mediastinum testis showing small hypoechoic areas. Arteriography showed thin or irregularly outlined testicular arteries, and the epididymal artery was lacking or appeared stenosed. Simple CTRT (without epithelial alteration) was found in both testes of 17 autopsied patients (all were elderly men) and in eight surgically removed testes from patients with sarcoma, tuberculous orchidoepididymitis, or hematocele. The most frequent epididymal lesion was bilateral efferent duct atrophy. In three patients, the rete testis presented nodular proliferation of calcifying connective tissue. CTRT with columnar transformation of the rete testis epithelium was observed in both testes from three patients with alcoholic cirrhosis, and in 10 surgically removed testes from patients with testicular tumor, cryptorchidism, or nonspecific orchitis. In cirrhotic patients, the efferent ducts appeared atrophied. In patients with testicular tumors, the efferent ducts were infiltrated by carcinoma in situ cells (CISs) and often contained granular material, cell debris, or hyaline globules. In both kinds of CTRT (without or with epithelial metaplasia), the most frequent seminiferous tubule lesions were tubular ectasia, hypospermatogenesis, tubular sclerosis, spermatogonium arrest, and sloughing of immature germ cells (spermatids and spermatocytes). The mechanism leading to CTRT might be mechanic (compression of the epididymis by an epididymal tumor or a spermatic cord tumor, or the result of a long-standing epididymitis or traumatic hemocele); ischemic (autopsied elderly men); hormonal (cirrhotic patients); malformative (cryptorchidism); or unknown (the remaining cases).