Sertoli cell tumour combined with lack of epididymis in a bull.

A case of a Sertoli cell tumour in one testis of an 111/2-year-old bull of the Red Danish breed is described. Ipsilaterally segmental aplasia of the Wolffian duct practically with aplasia of the epididymis occurred. The bull had served normally in an AI society until at the age of 11 years he acquired impaired semen quality. The tumour showed both a diffuse and a whirly palisade-forming pattern, and did not metastasize. The possible connection of the two abnormalities is discussed with respect to a recently published case in a newborn bull calf.