INTRODUCTION: Mounier-Kuhn syndrome is a rare disorder characterized by abnormal dilatation of the trachea and main bronchi, sometimes associated with tracheal diverticulosis, bronchiectasis, and recurrent lower respiratory tract infection.
CASE PRESENTATION: A 62-year-old female with a history of hypertension and type 2 diabetes presents with dyspnea on exertion for two months duration accompanied with a chronic cough productive of yellowish sputum for several months. She received several courses of antibiotics by her primary medical doctor with some improvement of her symptoms.She denied any history of fever, chills, hemoptysis, chest pain, tuberculosis, smoking, allergies, or familiar lung disease. Medications include nifedipine and glipizide. She is a married retired secretary, with two children. She denied alcohol and illicit drugs.Patient looked healthy, well developed, not in acute distress, afebrile, and examination was remarkable only for loud bilateral basilar crackles. Her BMP and CBC were normal. Her chest x-ray on lateral view showed enlarged trachea, and chest CT scan was significant for tracheobronchomegaly (trachea > 3.5 cm, and main bronchi >2cm in diameter), with bronchiectasis. A pulmonary function test revealed a mild obstructive ventilatory defect and decreased DLCO. Patient showed no evidence of secondary tracheobronchomegaly. Her symptoms appear related to bronchiectasis secondary to Mounier-Kuhn syndrome. Patient was placed on antibiotics, and pulmonary rehabilitation recomended.
DISCUSSIONS: The etiology of Mounier-Kuhn syndrome (Described in 1932), is unknown. A congenital defect or atrophy of the elastic and smooth muscle tissue of the trachea and main bronchi have been suggested. The familial form has been described as a possible recessive inherited disorder, and the acquired form as a complication of pulmonary fibrosis in adults or mechanical ventilation in preterm neonates. Secondary tracheobronchomegaly has been described in association with Ehlers-Danlos syndrome, Marfan syndrome, cutis laxa, and light chain deposition disease.Patients may have few or no symptoms. Excessive sputum production with occasional hemoptysis may occur and patients may develop dyspnea with respiratory failure as the lungs become progressively damaged. Chest radiograph may show increased caliber of the airways. Tracheomegaly is characterized by enlarged trachea (>3cm), right main bronchus (>2cm)or left main bronchus (>1.8cm) on chest CT. Tracheal diverticulosis is seen in 1/3 of patients. Asymptomatic patients require no specific therapy. Smoking cessation recommended. The management of symptomatic patients consists of intensive and appropriate antibiotic therapy and postural drainage. Tracheal stenting has been shown to be useful in advanced cases.
CONCLUSION: Mounier-Kunh syndrome should be consider in a patient with recurrent respiratory infections and chronic sputum production. A careful radiographic analysis of the central airways is obligatory.
DISCLOSURE: O. Ozir, None.