Primary Tracheal Leiomyoma in a Dog: A Case Report.

Primary tracheal neoplasia is uncommon in domestic animals and humans, and most reported tracheal tumours are malignant. To the authors' knowledge, this case represents the third confirmed case of tracheal leiomyoma reported in dogs. In human medicine, tracheal leiomyomas have also only been reported sporadically and account for approximately 1% of tracheal tumours. A 12-year-old spayed female Pit Bull was presented as an emergency because of an acute worsening of recurrent respiratory signs that were refractory to medical treatment. On initial evaluation, reduced mobility of both arytenoid cartilages was observed, and left arytenoid lateralisation was therefore performed. However, four days after the procedure, the dog continued to experience severe episodes of respiratory distress requiring orotracheal intubation. Subsequent bronchoscopy revealed an intraluminal tracheal mass occupying approximately 90% of the airway lumen. Because of this obstruction, an emergency temporary tracheostomy was performed caudal to the mass. Once the dog had been clinically stabilised, computed tomography was performed for surgical planning. Surgical treatment consisted of segmental tracheal resection and end-to-end anastomosis, with removal of a segment corresponding to 24% of the total tracheal length. Histopathological examination confirmed the diagnosis of tracheal leiomyoma. Complete surgical excision was achieved, supporting a favourable prognosis.