Rare canine tracheal leiomyoma case highlights airway workup gaps

A case report in Animals highlights an unusually rare diagnosis in canine airway disease: primary tracheal leiomyoma. The patient, a 12-year-old spayed female Pitbull, arrived in respiratory distress after chronic signs worsened and remained unresolved despite treatment and left arytenoid lateralization for bilateral laryngeal paralysis. Emergency bronchoscopy revealed a partially obstructive intraluminal tracheal mass, shifting the case from a presumed laryngeal problem to a tracheal surgical emergency. (preprints.org)

That rarity is part of the story. A 2025 review of tracheal neoplasia in dogs and cats identified 165 total cases across institutional data and published literature from 1961 through August 2024, with just 68 cases in dogs. In dogs, the most common tracheal tumors were osteochondroma, plasma cell tumor, chondrosarcoma, malignant epithelial tumors, and chondroma, underscoring how unusual a tracheal leiomyoma is in routine practice. The case authors state this is the third confirmed report of tracheal leiomyoma in a dog, and older PubMed-indexed reports from 1981 and 1981 support how sparse the veterinary literature has been on this tumor type. (journals.sagepub.com)

In this case, CT was central to defining the lesion after bronchoscopy detected it. The mass extended from the 9th to the 15th tracheal ring, occupied almost 100% of the lumen, arose from the dorsal tracheal ligament, and compressed the esophagus at the C3-C4 level, with no evidence of metastatic disease. Because airway compromise was severe, the team first placed a temporary tracheostomy caudal to the mass, then proceeded with segmental tracheal resection and end-to-end anastomosis. Ten tracheal rings were removed, representing 24% of the tracheal length, with 10 mm cranial and caudal macroscopic margins. The dog had no reported postoperative complications and no recurrence over two years. (preprints.org)

The report also shows how easily these cases can masquerade as more common respiratory disease. Thoracic and cervical radiographs did not show findings suggestive of tracheal neoplasia, and the mass was only diagnosed after worsening signs prompted emergency bronchoscopy. That fits with broader reference guidance from the Merck Veterinary Manual, which notes that tracheal tumors are particularly rare, that signs often reflect fixed upper-airway obstruction, and that definitive diagnosis depends on biopsy after imaging or tracheoscopy identifies the lesion. (preprints.org)

There wasn’t obvious veterinary expert commentary tied specifically to this report in the public domain, but the case aligns with patterns described in human literature on tracheal leiomyoma. Human case reports repeatedly note that these benign tumors can be mistaken for asthma or bronchitis because cough, wheeze, and dyspnea are nonspecific, and that bronchoscopy is often the key diagnostic step. Some human reports describe endoscopic management, but recurrence after bronchoscopic intervention has also been documented, while surgical resection remains the standard when anatomy or tumor attachment makes endoscopic removal less suitable. That context supports the authors’ decision not to attempt bronchoscopic excision here because of the lesion’s broad base and extent. (preprints.org)

Why it matters: For veterinary teams, the practical takeaway is less about the tumor’s biology and more about airway thinking. The authors note the main risk was functional obstruction rather than malignant behavior, and this dog’s outcome suggests complete resection can be curative when the lesion is localized and technically resectable. The case also reinforces the value of escalating the workup in refractory upper-airway cases, especially when clinical signs persist after an apparently plausible diagnosis, such as laryngeal paralysis. Bronchoscopy and CT may be worth earlier consideration when radiographs are nondiagnostic and the level of obstruction remains uncertain. (preprints.org)

It also has surgical and anesthetic relevance. The authors emphasize that tracheal resection demands close coordination between surgery and anesthesia to maintain airway control, and they describe using the temporary tracheostomy for initial ventilation before switching to orotracheal intubation as reconstruction progressed. In a case where nearly one-quarter of the trachea was removed, the absence of major perioperative complications adds a useful procedural datapoint for clinicians who may rarely encounter this anatomy under crisis conditions. (preprints.org)

What to watch: The next question is whether additional case accumulation helps define clearer diagnostic triggers and treatment thresholds for rare canine tracheal tumors. For now, this report mainly strengthens a clinical message: if a dog has persistent or worsening obstructive respiratory signs that don’t match the imaging or don’t improve as expected, tracheal neoplasia still belongs on the differential list. (journals.sagepub.com)