GENERAL CONSIDERATIONS

Canine Tracheal Tumors

•malignant tracheal tumors in dogs include OSA, CSA, MCT, ADC, LSA, and SCC

•benign tracheal tumors in dogs include chondroma, osteochondroma, ecchondroma-osteochondromal dysplasia, extramedullary plasmacytoma, and leiomyoma

•neoplasia of the thyroid gland, esophagus, lung, or aortic chemoreceptor can invade the trachea

•non-neoplastic tracheal masses include polyp, eosinophilic granuloma, nodular amyloidosis, tissue reaction to Filaroides osleri, chondromatous hamartoma, papillomatosis, and hyperplastic tracheitis

•bimodal age distribution with osteochondroma and ecchondroma-osteochondromal dysplasia in dogs < 2 years and other tumor types in dogs > 6 years

•osteochondroma and ecchondroma-osteochondromal dysplasia are benign osseocartilaginous tumors which grow in synchrony with the musculoskeletal system and should stop growing at skeletal maturity

DIAGNOSIS

Clinical Signs

•paroxysmal intermittent coughing of several weeks duration

•progressive worsening of dyspnea, stridor, and exercise intolerance

•occasional retching produces hemorrhagic discharge

•respiratory signs usually evident when > 50% diameter of airway obstructed

•large masses may be palpable especially in the dog

Imaging

•survey ± contrast bronchography with survey radiographs usually sufficient due to size of lesions at diagnosis

•other radiographic signs include pulmonary over-expansion, flattening of the diaphragm, and prominent pulmonary vasculature secondary to increased air content in the lower airways

•tracheoscopy provides positive diagnosis with samples collected for brush cytology and histopathology

•CT or MRI used in humans

TREATMENT

Surgical Resection

•resection and anastomosis

•± tracheal wall reconstruction or stenting

Other Treatment Options

•other options include radiation therapy, chemotherapy, endoscopic removal, and photodynamic therapy

Prognosis

•benign tracheal neoplasms have a good prognosis following complete resection

•short-term prognosis is good for dogs with tracheal tumors, but long-term outcome has not been assessed:

•survival times for osteochondroma > 6-8 months

•survival times for ecchondroma-osteochondromal dysplasia > 5-12 months

•survival times for leiomyoma > 6-7 months

•survival times for extramedullary plasmacytoma > 3 months

•survival times for CSA > 9-12 months