Idiopathic laryngotracheal stenosis: radiologic findings

Acquired nonneoplastic laryngotracheal stenosis can be either focal or diffuse. Diffuse tracheal stenosis is caused by sarcoidosis, tuberculosis, histoplasmosis, relapsing polychondritis, tracheopathia osteoplastica, and Wegener's granulomatosis. Focal tracheal stenosis, on the other hand, usually results from placement of an endotracheal or tracheostomy tube or from previous neck trauma. At our institution, since 1971, we have seen 49 cases of focal laryngotracheal stenosis that could not be attributed clinically or histologically to any one of the aforementioned causes. The purpose of this study was to study the radiologic features of these idiopathic laryngotracheal stenoses.

A retrospective review of records showed that radiologic studies were still available in only 15 of the 49 patients with idiopathic laryngotracheal stenoses. All 15 patients had radiographs and plain tomograms, and one patient had a CT scan of the neck. Three radiologists reviewed all the images.

The radiologic appearance was variable: the stenoses were from 2 to 4 cm long with a lumen between 3 and 5 mm in diameter at the narrowest portion. The narrowing was concentric and shaped like an hourglass in eight patients (53%) and was eccentric in the other seven (47%). The margins of the stenosis were smooth in nine patients (60%) and irregular and lobulated in six patients (40%). A dominant mass measuring approximately 1 cm in diameter was present in two patients (13%). No evidence of calcification or ossification was seen.

Idiopathic laryngotracheal stenosis produces focal stenosis of the cervical part of the trachea, 2 to 4 cm long. The lumen is severely compromised, measuring no more than 5 mm in diameter at its narrowest portion. The stenosis can be concentric or eccentric and can have either smooth or lobulated margins. Special attention should be paid to the airways when chest radiographs of patients with a history of prolonged dyspnea and wheezing are reviewed. The prevalence of focal stenosis of the larynx and the upper part of the trachea due to tracheal intubation has declined since the introduction of low-pressure, high-volume retention cuffs. Therefore, idiopathic laryngotracheal stenosis should be considered in the differential diagnosis in patients with focal narrowing of the airway.