Bilateral Testicular Mixed Germ Cell‐sex Cord‐stromal Tumours in a Stallion

Abstract

An 18-year-old Friesian stallion was examined approximately one week after reportedly presenting scrotal swelling due to torsion of the spermatic cords. Upon presentation no scrotal swelling was noted, the testes were normally oriented, and no abnormalities of the spermatic cords were noted. However, both testes were smaller than expected for a mature stallion and deep palpation revealed that the consistency of the testes was nodular. Ultrasonographic evaluation of the testes revealed diffuse heterogeneous parenchyma with multiple hypoechoic nodular areas. Grossly, the testicular parenchyma was effaced by multiple gray-tan nodules of varying consistency interspersed with gray-white bands of tissue. Microscopic analysis revealed multiple pleomorphic neoplastic foci disseminated throughout both testes. Histological and immunohistochemical features were atypical and consistent with the diagnosis of bilateral testicular mixed germ cell-sex cord stromal tumours. Bilateral testicular tumours and testicular mixed cell tumours are extremely rare in stallions and this is the first report of bilateral testicular mixed germ cell-sex cord-stromal tumours in a stallion. Our findings indicate that certain ultrasonographic characteristics are suggestive of testicular tumour and that immunohistochemistry markers can be used to better characterize testicular neoplasms in stallions.

Mature teratoma arising from an undescended testis in a horse: comparison between ultrasonographic and morphological features

“…Anechogenic band, representing a pseudocapsule, could be seen surrounding the testicle [3]. In cases of malignant mixed sex cord-stromal tumour, ultrasonographic evaluation of the testes revealed diffuse heterogeneous parenchyma with multiple hypoechoic nodular areas [5,22].…”

“…However, to our knowledge, scant information is available on the ultrasonographic appearance of different testicular tumours in the stallion [3,5,22] and imaging findings of intra-abdominal mature teratomas in undescended testis have been very rarely reported in the horse [8].…”

Gonadoblastoma in the Ovaries of a Lesser Galago (Galago senegalensis braccatus)

“…In contrast to GB, MGCSCST in people tends to occur in patients with normal phenotype or karyotype, is frequently unilateral, the sex cordstromal cells exhibit proliferative activity and in general lacks mineralization, extracellular matrix and the distinct histological patterns of GB. Most of the reported cases of GB or MGCSCST in animals, mainly in dogs and horses, occurred in the testes instead of the ovaries (Turk et al, 1981;Bertazzolo et al, 2004;Reis-Filho et al, 2004;Owston and Ramos-Vara, 2007;Talerman and Roth, 2007;Leach et al, 2008;Brito et al, 2009;Ramos-Vara and Miller, 2009). No previous cases of GB or MGCSCST have been reported in the gonads of non-human primates (Lowestine, 1986;Brack, 1988;Moore et al, 2003;Cianciolo et al, 2007;Cooper and Gabrielson, 2007;Wilkinson et al, 2008;Remick et al, 2009).…”

“…Gonadal tumours composed of a mixture of germinal cells and sex cord-stromal cells occur uncommonly in people and animals (Turk et al, 1981;Bertazzolo et al, 2004;Reis-Filho et al, 2004;Owston and Ramos-Vara, 2007;Talerman and Roth, 2007;Leach et al, 2008;Brito et al, 2009;Ramos-Vara and Miller, 2009). In people, these tumours are subclassified by the World Health Organization (WHO) into gonadoblastoma (GB) and mixed germinal cell-sex cord-stromal tumour (MGCSCST) (Talerman and Roth, 2007).…”

Mixed germ cell-sex cord-stromal tumor with a concurrent interstitial cell tumor in a ferret

“…In humans, two thirds of gonadoblastomas contain various amounts of interstitial cell component, and gonadoblastomas reported in a stallion have described that an MGSCT contained foci of interstitial cells that were considered interstitial cell-differentiation of neoplastic sex cord-stromal cell components [ 2 , 4 , 15 ]. Further, two cases of concurrent MGSCT and interstitial cell tumors have been reported in canines [ 12 , 13 ].…”