Testicular regression syndrome: a clinical and pathologic study of 11 cases

The vanishing or regressed testis is an entity well known to urologists and pediatric surgeons, affecting approximately 5% of patients with cryptorchidism. However, there is little review and discussion of this entity among pathologists with only 2 of 40 published reviews of testicular regression syndrome (TRS) found in the pathologic literature.

To assess recognition of TRS among a subset of pathologists and to determine the applicability of histologic criteria for TRS as published.

An 8-year retrospective review of cases submitted as atrophic or regressed testis was performed. Original diagnosis and diagnosis after review were compared to assess pathologic recognition of TRS. Pathologic assessment included identification of vas deferens, epididymis, dystrophic calcification, hemosiderin, dominant vein, pampiniform plexus-like vessels, and vascularized fibrous nodule formation. At minimum, the presence of a vascularized fibrous nodule (VFN) with calcification or hemosiderin or VFN with cord element(s) was required for diagnosis.

Medical records and pathologic specimens of patients undergoing surgery for cryptorchidism or with specimens reviewed at a medium-sized university hospital were analyzed.

The original diagnosis in 3 (23%) of 13 cases was that of TRS. On secondary review, 11 (85%) of 13 cases showed features consistent with TRS. The diagnoses both before and after review showed a concurrence of 23% (3/13 cases). Two (15%) of 13 cases were correctly recognized and diagnosed as TRS at primary review; 1 case originally thought to represent TRS was not confirmed. Pathologic features correlated well with those reported in the literature. Among all 13 cases, the 11 confirmed TRS cases showed VFN in 11 (85%), intranodular calcification in 8 (62%), intranodular hemosiderin in 9 (69%), vas deferens in 9 (69%), epididymal structures in 5 (38%), and a dominant venous structure in 11 (85%). The average size of the VFN was 1.1 cm.

A urologic and pediatric surgical problem, TRS may be unrecognized by many practicing pathologists. In the typical situation in which a blind ending spermatic cord is submitted for tissue analysis, characterization of such cases as consistent with regressed testis is desirable and achievable in a high percentage of cases. Pathologists may play a pivotal role in management of these patients since histologic confirmation of the testis as regressed reassures the surgeon and the family of the correctness of diagnosis and can eliminate the necessity for further intervention.