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Cancer of the Airway and Lung

Joanne L. Intile, DVM, DACVIM (Oncology)

College of Veterinary Medicine, North Carolina State University, Raleigh, NC, USA

Cancer of the Airway laryngeal tumors, and a possible overrepresentation of
Siamese cats developing tracheal tumors, there is no
Etiology/Pathophysiology typical age, breed, or sex predilection for laryngeal and
tracheal tumors in dogs and cats. However, younger
Tumors of the larynx and trachea are rare in dogs and animals with active osteochondral ossification sites are at
cats. The most common primary tumors of the canine in creased risk for developing benign tracheal osteocarti­
larynx are carcinomas, with squamous cell carcinoma laginous tumors.
occurring most frequently, followed by oncocytoma and
rhabdomyoma. Other reported laryngeal tumors
include mast cell tumor, extramedullary plasmacy­ History and Clinical Signs
toma, chondrosarcoma, osteosarcoma, melanoma, Patients with laryngeal tumors typically present with
lipoma, adenocarcinomas, fibrosarcoma, and papil­ signs directly related to the primary tumor, including
loma. Metastatic tumors from a distant site are rarely stridor, dyspnea, change in bark or voice, exercise intol­
reported. erance, weakness, or dysphagia. Ptyalism may also be
Feline primary laryngeal tumors include lymphoma, noted.
squamous cell carcinoma, and adenocarcinomas. Lei­ Patients with tracheal tumors present with similar
omyoma, basal cell carcinoma, and polyps are also symptoms as those with largyneal tumors, but are more
reported. likely to cough.
Secondary invasion of the larynx can result from ingrowth
of primary thyroid tumors or regional lymphoma.
The most common tracheal tumors in dogs include
benign tracheal osteocartilaginous tumors, leiomyoma, Diagnosis
adenocarcinomas, mast cell tumor, and extramedullary The diagnosis of a laryngeal tumor is often made upon
plasma cell tumor. In cats, adenocarcinomas, squamous direct visualization on awake or sedated oral exam. Oral
cell carcinoma, and other carcinomas are the most com­ exam provides limited information regarding the exten­
monly reported. siveness of the tumor, but the advantage is that tissue
biopsy samples can be obtained in a relatively noninva­
sive and economical manner.
Epidemiology
Cervical radiographs are helpful in localizing tumors
There are no known etiologic or epidemiologic factors of the distal portions of the larynx or trachea. Images
predisposing animals to developing laryngeal and tra­ may show a discrete soft tissue mass within the lumen of
cheal tumors. the trachea, and/or a calcified mass in cases of osteo­
chondromas/chondromas. Thoracic radiographs are
recommended to evaluate for the presence of metastatic
Signalment
disease and also to assess for evidence of aspiration
Other than a predilection for younger dogs to develop pneumonia, which may occur secondary to laryngeal
oncocytomas, for older cats to develop malignant dysfunction. Cervical ultrasound and tracheoscopy may be

Clinical Small Animal Internal Medicine Volume II, First Edition. Edited by David S. Bruyette.
© 2020 John Wiley & Sons, Inc. Published 2020 by John Wiley & Sons, Inc.
Companion website: www.wiley.com/go/bruyette/clinical