Immunohistochemical evaluation of the expression of anti-Müllerian hormone in mature, immature and neoplastic canine Sertoli cells.

In mammals, the earliest specific protein expressed by Sertoli cells (SCs) is the anti-Müllerian hormone (AMH), which induces the regression of Müllerian ducts and is produced by SCs until the functional maturation of the testes. The aim of this study was to evaluate the expression of AMH by canine SCs during testicular maturation and neoplastic transformation. Testes from two fetuses, 18 newborn puppies, five puppies aged 43-180 days and six adult dogs, and 24 canine Sertoli cell tumours (SCTs) were studied immunohistochemically for expression of AMH. Fifteen of the 24 SCTs were classified as typical, eight as lipid-rich and one was considered malignant based on evidence of lymph node metastasis. SCs from fetuses and neonatal puppies and puppies up to 45 days old expressed AMH, while SCs from older puppies and adults were negative. All SCTs expressed AMH, suggesting that AMH expression is a useful marker of immature and neoplastic canine SCs.