OBSTRUÇÃO URETERAL UNILATERAL POR NEOPLASIA MESENQUIMAL EM UM CANINO - RELATO DE CASO.

Ureteral obstruction due to neoplasms is rare in dogs and is considered an important differential diagnosis for ureteral obstructions in these animals. In this study, the diagnosis of unilateral ureteral obstruction due to a low-grade malignant mesenchymal neoplasm in a canine was made based on abdominal ultrasound analysis and histopathological analysis of the neoplasm. The patient was a female Maltese, not neutered, 12 years old and weighing 4,450 kg. She presented with bloody vulvar discharge. No other alterations were observed on physical examination. The initial clinical suspicion, based on the clinical signs presented, was uteropathy. The ultrasound scan showed results suggestive of mild uteropathy. An analysis of the other organs in the abdominal cavity revealed marked hydronephrosis of the right kidney with loss of right renal architecture, marked dilatation of the right ureter and right ureteral neoformation in the distal third, leading to ureteral obstruction and dilatation. The treatment plan employed was total nephrectomy of the right kidney and histology of the neoformation in the right ureter. The ureteral neoformation was sent for histopathological analysis, which was suggestive of low-grade malignant mesenchymal neoplasia. It is important to diagnose these cases early in order to provide appropriate treatment and, consequently, a better prognosis. In this way, this study aims to contribute to the national veterinary literature, which lacks studies on this subject, which, despite being rare, is relevant to the field. [ABSTRACT FROM AUTHOR]