Bilateral testicular tumours of mixed origin in a Kune Kune boar

A pet Kune Kune boar with an estimated age of 7 years old was presented with bilateral scrotal swelling. The right testicle and left testicle measured approximately 15–20 cm and 8–10 cm in diameter, respectively, and both testes felt abnormally firm. Ultrasound examination revealed soft tissue density with anechoic areas approximately 5 mm in diameter throughout; no normal testicular structure was evident. Bilateral castration was performed using a closed technique with the boar anaesthetised. Grossly, the cut surface of the right testicle was effaced by a multilobular to diffuse neoplastic proliferation, while the left testicle showed a small focal (1.5×1 cm) irregular whitish nodule (Fig 1). Histologically, the tissue from the right testis showed evidence of a diffuse, non-encapsulated neoplastic proliferation. The neoplastic cells were large and polygonal with eosinophilic cytoplasm and a large ovoid nucleus, consistent with a Leydig cell tumour (Fig 2). The tissue from the left testicle demonstrated a partially encapsulated proliferation. The neoplastic cells were elongated with small nuclei resembling Sertoli cells; they were confined within seminiferous tubules and displayed occasional mitoses and surrounded by abundant fibrovascular stroma (Fig 2). A section of spermatic cord from both testes was evaluated for lymphatic invasion with no evidence of neoplastic emboli his is an unusual bilateral presentation of testicular tumours with different origins. Concomitant Sertoli and Leydig cell tumours have been reported in a six-month-old boar; the tumours were unilateral and had widely metastasised (Mabara and others 1990). The lack of local lymphatic emboli indicated a low risk for metastatic spread; due to financial and practical constraints, no further investigation was carried out to determine if metastases were present in other organs. The owner reported the pig was alive with no health problems 16 months following the surgery.