A 14-year-old, intact male, mixed breed dog presented with history of testicular asymmetry and increase in left testicular volume. Although thoracic radiography showed no signs of metastasis, abdominal ultrasonographic examination revealed a large neoplastic structure whose origin could not be determined. On exploratory celiotomy, besides the identification of a large infiltrative mass adhered to external iliac arteries of both sides, there was lymph nodes enlargement. Orchiectomy with scrotal ablation was performed and the mass excised. The testicles and abdominal mass were further evaluated by histopathologic examination. Both samples consisted of neoplastic Sertoli cells with high mitotic rate and marked pleomorphism. After surgery, the animal developed vomition, anorexia, polydipsia and hematochezia. Fourteen days after surgery, the animal was discharged from the hospital. Sertoli cell tumor (SCT) exhibit low metastatic rate. Metastasis occurs mostly from intra-abdominal SCT. We report an extra-abdominal, intra-scrotal malignant SCT with large infiltrative abdominal metastasis.

Key words: Abdominal, Dog, Malignant, Metastasis, Sertoli cell tumor