Diagnosis

 Tracheobronchopathia osteochondroplastica

Findings

Computed tomographic images of the thorax demonstrate diffuse irregularity of the trachea and proximal mainstem bronchi characterized by the presence of multiple calcified or partially calcified nodules arising from the anterior and lateral tracheal walls.  These nodules result in irregularity of the mucosal surface and caliber of the trachea. Of note, the posterior tracheal wall is spared from involvement and no abnormal paratracheal soft tissue thickening or mediastinal adenopathy is seen.

Discussion

 Tracheobronchopathia osteochondroplastica (TO) is a benign condition characterized by the presence of multiple osteocartilaginous nodules or growths most commonly within the submucosa of the trachea but also seen within the submucosa of the proximal mainstem bronchi. These nodules are composed of hyaline cartilage and have areas of lamellar bone formation and are believe to arise from the perichondrium of the native tracheal cartilage.  Thus, they are found within the anterior and lateral walls of the trachea, and the posterior, non-cartilaginous tracheal wall is classically spared from involvement.

On CT, tracheobronchopathia osteochondroplastica manifests as thickening and nodularity of the tracheal cartilages. Tracheal involvement is typically diffuse and involvement of the proximal mainstem bronchi is common as well. Multiple nodules are seen protruding into the tracheal lumen, and these nodules may or may not be calcified. The tracheal lumen may be diffusely narrowed in cases of severe involvement.

Tracheobronchopathica osteochondroplastica can be distinguished from sarcoidosis by the absence of mediastinal adenopathy. Sarcoidosis also classically causes granulomatous lesions of the tracheal mucosa with involvement of the submucosa occurring less frequently. A similar appearance is seen with Wegner’s granulomatosis which is characterized by granulomatous inflammation of the mucosa and submocosa. Relapsing polychondritis manifests with marked paratracheal inflammation which is not seen in TO, and the submucosa and mucosa are typically not involved in relapsing polychondritis.

Kwong JS, Muller NL, Miller RR. Diseases of the Trachea and Main-Stem Bronchi: Correlation of CT Findings with Pathologic Findings. Radiographics 1992; 12: 645-657.

Restrepo S, Pandit M, Villamil MA, Rojas IC, Perez JM, Gascue A. Tracheobronchopathica osteochondroplastica: Helical CT Findings in 4 Cases. J Thorac Imaging 2004; 19: 112-116.

Kwong JS, Muller NL, Miller RR. Diseases of the Trachea and Main-Stem Bronchi: Correlation of CT Findings with Pathologic Findings. Radiographics 1992; 12: 645-657.