Case report of leiomyosarcoma, a very rare type of urinary bladder tumour

Abstract

Urinary bladder tumours account for approximately 1% of all tumours in dogs. The majority of them are epithelial in origin and malignant. Transitional cell carcinoma (TCC) is the most commonly diagnosed tumour of the urinary bladder. Malignant mesenchymal tumours in humans and animals are far less frequent than epithelial ones. Malignant mesenchymal urinary bladder tumours are represented by rabdomyosarcoma (RMS) and leiomyosarcoma (LMS). LMS occurs in older dogs, aged 7 - 12 years, and originates from the urinary bladder trigone and urethra, thus disturbing the urinary flow. LMSs are usually invasive, with a tendency to metastasize rapidly to the regional lymph nodes or abdominal organs, such as the liver, pancreas, kidneys, intestines and omentum. The aim of this report is to describe the clinical presentation, diagnostic approach and surgical treatment of the urinary bladder leiomyosarcoma that occurred in a Bernese Mountain Dog. The paper also highlights the latest diagnostic techniques for urinary bladder tumour detection, general rules of surgical resection and chemotherapy.