|Year : 2017 | Volume
| Issue : 1 | Page : 39-41
A case report of Mounier-Kuhn syndrome
Department of TB and Chest Diseases, Coimbatore Medical College, Coimbatore, Tamil Nadu, India
|Date of Web Publication||29-Dec-2016|
Dr. Keerthivasan Sivanmani
Department of TB and Chest Diseases, Coimbatore Medical College, Coimbatore, Tamil Nadu
Source of Support: None, Conflict of Interest: None
Mounier-Kuhn syndrome is a congenital abnormality characterized by tracheobronchomegaly as a result of atrophy or absence of elastic fibers and thinning of smooth muscle layer in trachea and main bronchi. The usual presentation is one of 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. We describe a case of an elderly man who presented with a recurrent respiratory infection who was subsequently diagnosed as Mounier-Kuhn syndrome.
Keywords: Bronchiectasis, diverticulosis, tracheobronchomegaly
|How to cite this article:|
Sivanmani K. A case report of Mounier-Kuhn syndrome. J Assoc Chest Physicians 2017;5:39-41
| Introduction|| |
Mounier-Kuhn syndrome is a congenital abnormality characterized by tracheobronchomegaly as a result of atrophy or absence of elastic fibers and thinning of smooth muscle layer in trachea and main bronchi. The usual presentation is one of 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. We describe a case of an elderly male who presented with a recurrent respiratory infection who was subsequently diagnosed as Mounier-Kuhn syndrome.
| Case Report|| |
A 70-year-old elderly male presented with the complaints of breathlessness on exertion for the past 2 months. Breathlessness was of Grade 1 severity on MRC grading and there was no orthopnea or paroxysmal nocturnal dyspnea. He gave a history of recurrent respiratory infection from his adolescence. He is a nonsmoker and nonalcoholic but a patient of Type 2 diabetes mellitus on oral anti-diabetic drugs. Physical examination showed bilateral crackles in the basal regions. His complete blood count revealed a total count of 11,000 cells/mm3, differential count of P65%, L30%, E3%, hemoglobin of 11.5 g/dl, and erythrocyte sedimentation rate of 20 mm in ½ h, 35 mm in 1 h. His random blood sugar was 137 mg%, urea 23 mg%, and creatinine 0.93 mg%. His chest X-ray posterior–anterior view showed bilateral lower zone reticular opacities [Figure 1]. With the history and radiological features, a differential diagnosis of interstitial lung disease and bronchiectasis were made. He was further subjected to high-resolution computed tomography (CT) which showed bronchiectatic changes in both lower lobes [Figure 2]. Furthermore, the trachea and bronchi were abnormally dilated. The diameter of the trachea at the level of aortic arch was 3.8 cm and diameters of the right main bronchus and left main bronchus were 2.9 and 2.8 cm, respectively [Figure 3],[Figure 4],[Figure 5]. CT also showed air pockets around the trachea which lead to the suspicion of the tracheal diverticulum. We proceeded with the fiberoptic bronchoscopy which showed posterior tracheal diverticulum in the subglottis region [Figure 6]. Furthermore, the trachea and both main bronchus were dilated with collapsibility on expiration. Minimal secretions from both lower lobes were noted, and lavage was taken. Microbiological analysis of the lavage fluid for acid-fast Bacilli was negative, fungal smear negative, and no growth in culture.
|Figure 2: High-resolution computed tomography lung showing cystic bronchiectatic changes in lower lobes|
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|Figure 3: Mediastinal window at the level of aortic arch showing diameter of trachea 3.67 cm|
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|Figure 6: Bronchoscopy showing posterior tracheal diverticulosis and dilated trachea|
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| Discussion|| |
Mounier-Kuhn in 1932 described a rare entity characterized by dilatation of trachea and bronchi with the absence of elastic fibers and thinning of smooth muscles which was named after them as Mounier-Kuhn syndrome or congenital tracheobronchomegaly. Most cases present in the third or later decades with a history of recurrent respiratory infections. A broad spectrum of clinical abnormalities has been documented ranging from tracheal diverticulosis, bronchiectasis, and pulmonary fibrosis., The other conditions such as Marfan syndrome, Ehlers–Danlos syndrome, and cutis laxa may also present with secondary tracheobronchial dilatation.
Mounier-Kuhn syndrome can be diagnosed from a plain CT by measuring the transverse diameter of trachea and bronchi. On CT scan, the diagnosis is made when the transverse diameter of the trachea measures >3 cm and that of the right and left main bronchi exceeds 2.4 and 2.3 cm, respectively. In our case, the diameter of trachea was 3.8 cm and that of the right and left main bronchus were 2.9 and 2.8 cm, respectively. Furthermore, in our case, the high-resolution CT showed the presence of bilateral bronchiectasis and bronchoscopy showed tracheal diverticulosis which confirmed the diagnosis.
The cause of tracheobronchomegaly is not entirely known although a genetic link has been suggested with findings of radiographic abnormalities in the siblings. The diagnosis is usually made in adulthood but in some patients it is diagnosed after the fifth decade as in our case due to indistinguishable clinical manifestations from chronic bronchitis and bronchiectasis. Usually, the management is symptomatic with antibiotics, bronchodilators, and postural drainage. The generalized nature of disease limits any possible benefit of surgical resection. However, a few cases have been reported where Y-shaped tracheobronchial stent placement helped the trachea to remain open with significant clinical improvement.
| Conclusion|| |
In a case of recurrent respiratory infections with radiological picture suggestive of bronchiectasis, tracheobronchomegaly can be easily overlooked particularly with plain films. Hence, a CT scan is mandatory in these types of cases to rule out underlying predisposing conditions such as this.
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Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6]