title: 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.
authors.affiliation: Department of Clinical Studies, School of Veterinary Medicine, New Bolton Centre, University of Pennsylvania, Kennett Square, Pennsylvania 19348, USA. lfcbrito@lycos.com
authors.forename: L F C
authors.initials: LF
authors.lastname: Brito
authors.forename: J B
authors.initials: JB
authors.lastname: Engiles
authors.forename: R M
authors.initials: RM
authors.lastname: Turner
authors.forename: L M
authors.initials: LM
authors.lastname: Getman
authors.forename: A
authors.initials: A
authors.lastname: Ebling
mesh_terms: D000818:Animals; D006734:Horse Diseases / Q000175:diagnosis*; D006736:Horses; D007150:Immunohistochemistry; D008297:Male; D009373:Neoplasms, Germ Cell and Embryonal / Q000175:diagnosis / Q000473:pathology / Q000662:veterinary*; D019009:Proto-Oncogene Proteins c-kit / Q000032:analysis; D018312:Sex Cord-Gonadal Stromal Tumors / Q000175:diagnosis / Q000473:pathology / Q000662:veterinary*; D013736:Testicular Neoplasms / Q000175:diagnosis / Q000473:pathology / Q000662:veterinary*; D014463:Ultrasonography / Q000662:veterinary
chemical_list: D019009:Proto-Oncogene Proteins c-kit