Cystic dilatation of the rete testis.

Seminiferous tubular ectasia at the level of the mediastinum testis is a recently recognized rare benign condition. It is often bilateral, and usually occurs in elderly men. It is commonly associated with epididymal abnormalities (e.g. spermatocele, epididymal cysts or epididymitis), and it shares a common location (within the mediastinum testis) with cystic dysplasia of the testis and testicular cysts. Obstruction caused by trauma or inflammation is thought to be a causative factor in seminiferous tubular ectasia and testicular cysts.