Leiomioma intestinal intrapélvico em cão - desafio diagnóstico e terapêutico / Intrapelvic intestinal leiomyoma in a dog - diagnostic and therapeutic challenges

ABSTRACT

Background: Rectal tumors are uncommon in dogs and cats. The clinical signs result from intra- and extraluminal compression. Diagnosis and treatment of rectal tumors are challenging due to their intraplevic location. Owing to considerable bonesuperposition, computed tomography is the best exam to evaluate the tumor and plan surgery; however, poor availabilityand high costs may hinder its use. The objective of this case report is to describe the successful use of a combination ofdiagnostic techniques, namely transrectal ultrasound, transrectal fine-needle aspiration, and colonoscopy, for diagnosisand surgery planning in a case of intrapelvic intestinal leiomyoma in a dog.Case A 13-year-old female mongrel dog with tenesmus, low stool production, and hematochezia for two months was presented for examination. During this two-month period, a symptomatic treatment was administered, but there was no clinicalimprovement. In the clinical evaluation revealed a painless mass on the left dorsolateral region, at a depth of around 4 cm,with considerable luminal reduction. Abdominal ultrasound revealed a mass close to the descending colon; however, bonesuperposition precluded identification of its origin or delimitation of its boundaries. The patient was subjected to transrectalultrasound imaging, colonoscopy, and cytological examination of fine-needle aspiration biopsy material collected under generalanesthesia. The mass was located at the final portion of the descending colon; it was extraluminal, and measured around 7 x7 cm. The integrity of the intestinal wall was preserved. Next, radiographic examination of the thorax using three projections(ventrodorsal, left lateral, and right lateral) was performed to check for metastases, and no alteration was detected. Cytologysuggested presence of leiomyoma. The patient underwent exploratory laparotomy with pubic osteotomy for intrapelvic access...