Clinicopathological and immunohistochemical evaluation of oesophageal leiomyosarcoma in a dog

Abstract

Oesophageal leiomyosarcoma is a malignant neoplasm of smooth muscle fibres that is infrequently reported in the literature. Because of the importance of definitive diagnosis and the low incidence of this tumour in dogs, it was reported a case of oesophageal leiomyosarcoma in a dog. A 13-yearold intact male Rottweiler presented regurgitation, hyporexia, and chronic weight loss. After an imaging examination, tumour in the thoracic oesophagus was suspected and a biopsy was sugested for definitive diagnosis. However, the owner did not permit the procedure. Six months after the clinical diagnosis, the patient was brought for evaluation of anorexia, apathy, and severe dyspnoea. Because of the patient’s clinical signs and lack of response to emergency treatment, he was euthanized. Upon necropsy, it was identified the neoplastic formation, previously identified in the radiographic examination in the thoracic oesophagus, near the diaphragm. Histopathology revealed a proliferation of mesenchymal cells, and the diagnosis of leiomyosarcoma was confirmed by immunohistochemical examination. Despite the low incidence of oesophageal leiomyosarcoma, it should be included as a differential diagnosis for animals with chronic regurgitation.