Severe Degenerative Changes in Cryptorchid Testes in Japanese Black Cattle

Abstract

This is a histopathologic and endocrinologic study of 6 calves diagnosed with cryptorchidism. Cases 1–3 were diagnosed as resembling testicular regression syndrome. In cases 1 and 2, the extracted tissue was a small, firm, gray-white mass, and there was lack of obvious testicular tissue in case 3. Histopathologically, the excised tissue in cases 1–3 was a fibrotic testicular remnant with inflammation, mineralization, hemosiderin-laden macrophages or lipofuscin-laden macrophages, and lack of germ cells and interstitial endocrine cells. These findings were compared with cases 4–6, which were diagnosed as testicular hypoplasia due to cryptorchidism. These cases had small but otherwise grossly unremarkable intra-abdominal testicular tissue and histologically had a few germ cells and sustentacular cells with arrested spermatogenesis and an increase in interstitial endocrine cells. Cases 1–3 had more severe degenerative changes compared with cases 4–6. In case 2, the average diameter of the seminiferous tubules was much smaller than in cases 4–6, and there were few tubule cross sections. Anti-Müllerian hormone (214 pg/ml) was detected in the plasma of case 2. Based on the macroscopic and histopathologic findings as well as endocrinologic profiles, the testicular degeneration in cases 1–3 was considered similar to that of testicular regression syndrome. In this condition, it is thought that a normally developing intra-abdominal testis undergoes degeneration due to heat or a vascular disorder such as torsion.

Stereological study of testes following experimentally-induced unilateral cryptorchidism in rats

“…In this study, greater interstitial volumes were consistently observed in the cryptorchid testes compared to the other groups. Our findings are consistent with a previous study on cryptorchid calves in which the hypoplastic cryptorchid testes presented an increased number of interstitial endocrine cells, marked fibrosis, and arrested spermatogenesis [40].…”

“…The testes of five rats in each group were removed at designated time points (40,63, and 90 days after birth) [19]. The rats were euthanized by cervical dislocation at each of the three time points, the testes were excised, and sperm analysis and stereology were undertaken to determine various parameters.…”