Mounier Kuhn bronchoscopic and radiological findings.

A. Hanna*^a (Dr), Y. Uzunhan^b (Prof), A. Girault^c (Dr), D. Mitilian^c (Dr), H. Mal^d (Prof), J. Le Pavec^a (Dr), G. Dauriat^a (Dr)

^a Interventional bronchoscopy unit, Department of Pulmonary medicine and Lung Transplantation, Marie Lannelongue Hospital., Le Plessis Robinson, FRANCE ; ^b Avicenne hospital, Bobigny, FRANCE ; ^c Department of Thoracic, Vascular Surgery and Heart-Lung Transplantation, Marie Lannelongue Hospital., Le Plessis Robinson, FRANCE ; ^d Bichat hospital, Paris, FRANCE

* amirkmaurice@gmail.com

Introduction:

Mounier-Kuhn syndrome, is a rare clinical and radiologic condition characterized by marked tracheobronchial dilation and recurrent lower respiratory tract infections. It is characterized by tracheobronchial dilation secondary to atrophy of the muscular and elastic tissues in the trachea and main bronchial walls. Diagnosis is established with computed tomography (CT) confirmed by bronchoscopy, as well as pulmonary function testing.

Case presentation:

A 32 years old female patient followed up for a Mounier Kuhn syndrome. She was referred to our center for lung transplantation evaluation. CT scan showed tracheobronchomegaly, 40mm tracheal diameter and 85 mm for the left main bronchus (Fig: 1,2), multiple tracheal diverticula mainly in the posterior tracheal wall, varicose and cystic bronchiectasis extended to the distal bronchi. Fiberoptic bronchoscopy was consistent with the CT findings (Fig: 3,4,5). Pulmonary function test: FVC 63% 2180mL, FEV1 42% 1270mL, FEV1/FVC 58%, TLC 99% 4840mL, RV 191% 2760mL, DLCO 48%, KCO 68%.

Discussion and conclusion:

Mounier-Kuhn syndrome is secondary to a thinning of the muscular mucosa and atrophy of the longitudinal muscle and elastic fibers of the tracheobronchial tree. As a consequence, tracheal diverticulosis and dilatations in the posterior membranous wall appear, along with bronchiectasis that tend to be cystic in appearance. Overall, there is an impairment of mucocilliary clearance, with an ineffective cough, which predisposes the patient to recurrent lower respiratory tract infections.

Three subtypes were described in literature: type 1 with subtle symmetrical dilation of trachea and major bronchi; type 2 with more obvious dilation and eccentric diverticula; type 3 with diverticula that extend to the distal bronchi. Treatment ranges from respiratory physiotherapy for airway clearance to endobronchial stenting in severe cases. Lung transplantation is not technically possible due to absence of bronchial airway required for the anastomosis.

Disclosure of funding source(s): none