Bilateral lymphangiomatous testicular lesions in a lamb

Bilateral testicular enlargement was recognized in a young lamb; both gonads were largely replaced by a mass composed of multiple cystic spaces. Positive immunohistochemical staining for factor VIII-related protein indicated that the cysts were lined by endothelial cells. The precise nature and origin of the lesions is unclear; they might represent hamartomas or benign tumours or may be a result of lymphatic obstruction.