Bilateral diffuse seminoma in equines

Abstract

Seminoma is a testicular neoplasm, originating from the germ cells of the spermatic testicular epithelium, and is histologically classified as diffuse and intratubular. Affected animals present increased testicular volume, local pain, difficulty in locomotion, infertility, anorexia and lethargy. A male horse, not castrated, of the Mangalarga Marchador breed, aged 15 years, was treated at the Veterinary Hospital of the Universidade Estadual do Norte Fluminense, with the main complaint being an increase in the volume of the testicle and progressive weight loss over a period of 5 years. On clinical exa-mination, the animal presented a thin body score, pale mucous membranes and mild dehydration. On palpation of the left testicle, it was possible to observe an ovoid-shaped mass, hard consistency, attached to the scrotum, ulcerations on the ventral surface of the scrotum, and no pain on palpation. The right testicle demonstrated preserved consistency and shape upon palpation. An ultrasound examination was performed, which made it possible to visualize the right testicle with preserved morphology, and the left testicle with significant changes, suggestive of a neoplastic process. The animal was sent for bilateral orchiectomy, using the open technique, in the supine position, under general inhalation anesthesia. In the macroscopic evaluation, the dimensions of the left testicle were 41 cm long, 22 cm wide, and 16 cm high. The right testicle was atrophied and brownish when cut, and fragments were sent for histopathological examination. In the histopathological evaluation, cellular pleomorphism, slightly acidophilic cytoplasm, multifocal lymphocytic infiltrate and high mitotic index were observed, classified as bilateral diffuse seminoma. Postoperatively, conventional therapy based on flunixin meglumine and benzathine penicillin was instituted. Daily dressings of the surgical wound were performed with 2% polvidine iodine. Ten days after the surgical procedure, the animal was discharged with a favorable prognosis.