Surgical Resection of a Testicular Seminoma in a Guinea Pig (Cavia porcellus)

An approximately 6-year-old intact male guinea pig (Cavia porcellus) presented with a 5- to 6-day history of an enlarged left testicle. Physical examination revealed a firm mass, roughly 5 cm in diameter, encompassing the region of the left testicle. All other organ systems appeared unremarkable. Routine bilateral orchiectomy was performed, and the enlarged testicle submitted for histopathologic analysis. Histopathologic results confirmed the presence of a seminoma with intravascular invasion. The patient made a complete recovery, and contrast-enhanced computed tomography, performed 4 months postoperatively, did not reveal the presence of local recurrence or metastatic disease. This report describes and further demonstrates that surgical resection, when used as the sole treatment modality, may provide substantial disease-free resolution of testicular seminomas in guinea pigs.