Teaching Case

A 68-year-old man referred to the pulmonology consultation due to progressive worsening dyspnoea and persistent dry cough, with normal pulmonary function tests. He reported no other symptoms and physical examination was unremarkable.

Computed tomography showed thickened tracheal cartilage with multiple nodules projecting into the airway lumen, some calcified, sparing the posterior membrane.

Bronchoscopy showed nodular excrescences protruding throw-out the entire extent of the anterolateral tracheal wall, without involvement of the posterior membranous wall, also affecting the proximal main bronchi, with intact mucosa.

Tracheobronchopathia osteochondroplastica is an uncommon idiopathic disorder affecting the tracheobronchial tree characterized by abnormal chondrification and ossification of cartilages [1,2].

It usually affects patients between the fourth and seventh decades of life, without gender preference [2,3].

Although roughly 400 cases have been published [2,4], it is probably more frequent as reported, as it can be asymptomatic of present with non-specific symptoms like chronic cough, dyspnoea, haemoptysis, wheezing and recurrent pulmonary infections [1,3,5,6].

The location of the lesions and degree of airway obstruction determine the results of the pulmonary test, ranging from a normal spirometry in mild cases to an obstructive pattern in patients with extensive disease [2].

Diagnosis is frequently incidental by computed tomography showing irregularly thickened tracheal wall, with anterolateral submucosal nodules, with or without calcification, that protrude to the tracheal lumen. It usually affects the lower third of the trachea, although it can extend anywhere from the larynx to the main bronchi, where cartilaginous rings are still present [1,2,4]. The membranous posterior wall is always spared, allowing distinction from other diseases as amyloidosis that tends to affect the airway concentrically [4,5]. In relapsing polychondritis (RP), another differential diagnosis, the posterior trachea wall is also spared, however, the presence of focal coarse calcification and ossification and absence of other involved systems, as in the case we present, favours tracheobronchopathia osteochondroplastica over relapsing polychondritis [4,6].

Bronchoscopy is considered the gold standard for diagnosis and allows better evaluation of disease extent. Multiple whitish and hard nodules measuring 1 to 10 mm are seen protruding into the airway lumen, sparing the posterior tracheal wall [1,2,5].

The need for histopathology is controversial, as direct visualization of the nodules is usually sufficient for diagnosis [1,2].

In symptomatic cases, management includes a combination of antitussives, inhaled bronchodilators, steroids, antibiotics or clearance therapies. The progression of the disease is benign with long-term stability, but a minority of patients can present with important airway obstruction requiring more invasive bronchoscopic or surgical interventions [1,2,3].

Take-home message

CT provides a non-invasive examination of the trachea wall, lumen and surrounding tissues, providing an adequate evaluation of diffuse tracheal diseases.

Although bronchoscopy is the gold standard for the diagnosis of tracheobronchopathia osteochondroplastica and evaluation of disease extent, CT showing irregular, nodular thickening of the anterolateral tracheal wall, with frequent calcification, is highly suggestive and if often the first clue to the diagnosis.

Written informed patient consent for publication has been obtained.