Anatomopathological features of uterine tube adenoma in a female dog

The uterine tube is part of the female reproductive system responsible for connecting the ovary to the uterus. Neoplasms originating from the uterine tube are rare in both animals and humans, with few reports available in the veterinary literature. A 7-year-old mixed-breed bitch was presented with clinical signs of lethargy, weight gain, and abdominal distension. Ultrasonography and computed tomography revealed a large abdominal mass. The patient underwent exploratory laparotomy for surgical excision of the mass, which was found adhered to the right ovary. Grossly, the mass measured 27.5 × 22.5 × 5.5 cm, had a soft consistency, irregular contours, reddish coloration, and a papillary appearance. Histopathological evaluation revealed well-differentiated papillary projections lined by ciliated columnar epithelial cells, with positive expression of estrogen and progesterone receptors and low Ki-67 labeling index, supporting the diagnosis of uterine tube adenoma. Although these tumors may reach considerable dimensions, they are generally associated with a favorable prognosis. In the present case, the diagnosis was established based on the correlation of clinical, morphological, and histopathological findings.