Mounier-Kuhn Syndrome: Report of 8 Cases of Tracheobronchomegaly With Associated Complications

Abstract

Mounier-Kuhn syndrome is a rare congenital abnormality characterized by atrophy or absence of elastic fibers and thinning of smooth muscle layer in the trachea and main bronchi. These airways are thus flaccid and markedly dilated on inspiration and collapsed on expiration. First- to fourth-order bronchi are affected. There is an increase in dead space, tidal volume and diminished clearing of secretions. The usual presentation is recurrent respiratory tract infections with a broad spectrum of functional impairment ranging from minimal disease with preservation of lung function to severe disease in the form of bronchiectasis, emphysema and pulmonary fibrosis, ultimately culminating in respiratory failure and death. A congenital connective tissue weakness, in combination with inhalation of irritants like cigarette smoke and air pollution, are raised as possible factors in the development of this syndrome. Eight cases of tracheobronchomegaly with its associated complications are reported. Computed tomography scan of the chest was used for the diagnosis of tracheobronchomegaly. Treatment is mainly supportive with chest physiotherapy and antibiotics; however, there are a few reported cases where insertion of a tracheal stent resulted in some success.

Mounier-Kuhn syndrome: A rare cause of recurrent respiratory tract infections

“…In adults, measuring diameters for the trachea, the right main bronchus and the left main bronchus, over 30 mm, 24 mm, and 23 mm, respectively, are diagnostic in the chest radiograph. Trachea and main bronchi diameters for the diagnosis of Mounier-Kuhn syndrome in the CT scans are given in Table 1 (5). Tracheobronchomegaly is often accompanied by bronchiectasis and tracheal diverticula.…”

Síndrome de Mounier-Kuhn: achados radiológicos e apresentação clínica

“…Mounier-Kuhn syndrome or tracheobronchomegaly (TBM) is a rare disease characterized by atrophy or absence of elastic fibers and thinning of the smooth muscles in the trachea, main bronchi and first-to fourth-order bronchi (1) ; consequently, the flaccid airways become widened during inspiration and collapse during expiration (1) . Although the findings have been recognized by Cyhlarz in autopsies since 1897, only in 1932 Mounier-Kuhn associated endoscopic and radiological findings of widened airways with recurrent infections of the respiratory tract .…”

“…A subtle predominance of the disease is observed in men, at the third or fourth decades of life, but the exact prevalence is still to be determined, with very few cases reported in the literature (1-3) . It is thought that the conjunctive tissue weakness associated with inhalation of air pollutants and tobacco smoke play a key role in the development of such a syndrome (1) . The present study is aimed at describing the main clinical, radiographic and high resolution computed tomography (HRCT) findings in TBM, also known as MounierKuhn syndrome.…”

“…fections, secretion accumulation and ineffective cough (1,2) . A subtle predominance of the disease is observed in men, at the third or fourth decades of life, but the exact prevalence is still to be determined, with very few cases reported in the literature (1-3) .…”

The Association of Mounier-Kuhn Syndrome and Pulmonary Aspergillomas: A Case Report

“…MKS is diagnosed radiographically and bronchoscopically when chest CT reveals (female/male) tracheal transverse diameters >21/25 mm and sagittal diameters >23/27 mm, and when the transverse diameters of the right and left main bronchi are >19.8/21.1 and >17.4/18.4 mm, respectively (3,4). MKS features three subtypes: the first is characterized by slight symmetrically diffuse enlargement of the major airways; the second obvious and distinct airway enlargement with diverticula; and the third diverticula or sacculations extending to the distal bronchi (1,4).…”