[Intrapelvic leiomyoma causing concurrent colonic and urethral obstruction in a dog]

An 8-year-old female spayed dog was presented due to simultaneous inability to defecate and urinate. During digital rectal examination a smooth, rounded, firm-elastic mass was detected. Laboratory results showed a 6-fold elevation of serum lactate dehydrogenase activity. Ultrasonographic, radiographic and computed tomography findings raised the suspicion of a leiomyoma. An ultrasound-guided fine needle aspiration biopsy was performed under mild sedation but cytologic evaluation was inconclusive. During laparotomy the mass was located at the colorectal transition. It was completely removed while keeping the intestinal wall intact. The results of the histopathological examination and immunohistochemistry confirmed the initial tentative diagnosis of a leiomyoma. Postoperatively the patient was able to pass urine and feces spontaneously. Six months later the dog presented clinically unremarkable. Abdominal ultrasound and rectal examination exhibited no signs of recurrence. Lactate dehydrogenase activity was only marginally increased.