Flexible bronchoscopy and mechanical ventilation in managing Mounier-Kuhn syndrome: a case report

CONTEXT

Mounier-Kuhn syndrome is a rare congenital condition with distinct dilatation and diverticulation of the tracheal wall. The symptoms may vary and the treatment usually consists of support.

CASE REPORT

The patient was a 60-year-old male with recurrent hospital admission. He was admitted in this case due to dyspnea, cough and sputum production. An arterial blood sample revealed decompensated respiratory acidosis with moderate hypoxemia. A chest computed tomography (CT) scan showed dilatation of the trachea and bronchi, tracheal diverticula and bronchiectasis. Flexible bronchoscopy was performed, which revealed enlarged airways with expiratory collapse. Furthermore, orifices of tracheal diverticulosis were also detected. Non-invasive positive pressure ventilation (NPPV) was added, along with long-term oxygen therapy. At control visits, the patient's clinical and laboratory findings were found to have improved.

CONCLUSION

Flexible bronchoscopy can be advocated for establishing the diagnosis and non-invasive mechanical ventilation can be used with a high success rate, for clinical wellbeing in Mounier-Kuhn syndrome.

A case of tracheobronchomegaly

Tracheobronchomegaly (Mounier-Kuhn syndrome) is a rare condition characterized by an abnormally enlarged trachea and main bronchi. Herein, we present a case of 79-year-old male with idiopathic pulmonary fibrosis and acute hypoxemic respiratory failure due to multilobar pneumonia. Computed tomography of the chest demonstrated a markedly dilated trachea, with the transverse diameter of 31mm and the sagittal diameter of 30mm. The clinical manifestations as well as its diagnosis, classification, and treatment are discussed.

[Tracheobronchomegaly: a report of 3 cases and literature review]

OBJECTIVE

To analyze the clinical, radiological, and pathological characteristics of tracheobronchomegaly (TBM, Mounier-Kuhn syndrome).

METHODS

The clinical, radiological and pathological characteristics of 3 cases of TBM were analyzed, and the literatures were reviewed.

RESULTS

All 3 patients were men, between the age of 58 - 71 years old. From the onset to diagnosis, the shortest time was 2 months, and the longest 43 years. The most usual presentations included recurrent cough and sputum, and occasional haemoptysis. In the advanced stage of the disease, patients would present shortness of breath and the symptoms associated with respiratory failure because of the reduction in pulmonary function. All the diagnoses were confirmed by X-ray and CT of the chest finding that the trachea and the main bronchi dilated markedly. After anti-infection treatment, all patients recovered. Mounier-Kuhn syndrome was 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 were thus flaccid and markedly dilated on inspiration and collapsed on expiration. The usual presentation was 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. Computed tomography scan of the chest was used for the diagnosis. Treatment was mainly supportive with chest physiotherapy and antibiotics.

CONCLUSIONS

Mounier-Kunh syndrome should be suspected in patient with recurrent respiratory infections and chronic sputum production. A careful analysis of the central airways at the chest radiograph of these patients is required.

An unusual cause of spontaneous pneumothorax: the Mounier-Kuhn syndrome

We present the case of a 54-year old woman referred to our service with an unusual presentation of an under-diagnosed condition. A life-long non-smoker, she was referred to respiratory services by our emergency department with a left sided pneumothorax, progressive dyspnoea on exertion, and recurrent chest infections. Subsequent investigation yielded findings consistent with Mounier-Kuhn syndrome (Tracheobronchomegaly), a condition characterised by marked dilatation of the proximal airways, recurrent chest infection, and consequent emphysema and bronchiectasis. Although rarely diagnosed, some degree of Mounier-Kuhn syndrome may occur in up to 1 in 500 adults.

[An unusual association: tracheobronchomegaly with a normal pulmonary function test]

Tracheobronchomegaly is a rare condition characterised by marked dilation of the trachea and the main bronchi. The clinical presentation of this disease is nonspecific and the diagnosis is based on the radiological features, especially computed tomography of chest. Pulmonary function tests are often abnormal showing airflow limitation with increased residual volume. The authors report a rare case of a 31-year-old man presenting tracheobronchomegaly is normal pulmonary function test.

Mounier-Kuhn syndrome: a rare cause of severe bronchial dilatation with normal pulmonary function test: a case report

Tracheobronchomegaly (TBM) (Mounier-Kuhn syndrome) is dilatation of the trachea and major bronchi because of atrophy or absence of elastic fibers and smooth muscle cells. We present a case of TBM with normal pulmonary function test (PFT). The patient was a 37-year-old man with increasing productive cough and without fever, wheezes, chest pain, weight loss or any respiratory disease. Chest helical computed tomography (CT) scan showed tracheomegaly with transversal diameters of the trachea of 44mm. CT scan showed collapse of the trachea. Few large diverticular out-pouching and openings in the trachea was seen in bronchoscopy. PFT results were normal. PFT in large airway disorders may be normal while abnormalities may indicate underlying small airway disorder. An underlying small airway disorders is responsible for abnormal reports in PFT of these patients. We may need to re-evaluate the role of PFT within follow-up of patients with large airway disorder.

[Mounier-Kuhn syndrome (tracheobronchomegaly)]

The case presents a 43 years old man, cigarette smoker, exposed to wood dust at work, with chronic, ineffective cough symptoms, limited physical exertion and recurring respiratory system infection. Disorders appeared at the age of 33 after severe double-sided pneumonia. Despite the lack of active clinical infection the following microorganisms: Pseudomonas aeruginosa and Staphylococcus aureus MSSA were isolated from patient bronchi mucus. Diagnosis followed image examination (CT, virtual bronchofibroscope). The following was recommended: quitting smoking, avoiding dust exposure at work, physiotherapy to ease mucus removal from bronchi and preventive vaccination. Tracheobronchomegaly consists in trachea clearance and central bronchi widening which disturbs air flow in air-passages and decreases cough effectiveness. Main symptoms are: paroxysmal cough, recurring bronchi inflammation and pneumonia resulting in mucus residing in air-passages.

Tracheobronchomegaly-Mounier-Kuhn syndrome

Tracheobronchomegaly is a rare disorder of uncertain etiology, characterized by marked dilatation of the trachea and major bronchi, associated with tracheal diverticulosis, bronchiectasis and recurrent respiratory tract infection. We are reporting a 60-year-old man from the Kingdom of Saudi Arabia with this condition and review the literature for such a rare entity.

Rapidly progressing case of Mounier-Kuhn Syndrome in early childhood

Reports of Mounier-Kuhn Syndrome in childhood are extremely rare, as it usually presents in the third or fourth decades. In the only other report of a case diagnosed in early childhood, the child was well at the time of publication. We report on a 15-month-old boy who presented with his first respiratory illness at age 3 months. His disease course was more severe than previously reported. Diagnosis was characteristically delayed until acute respiratory failure complicated a respiratory tract infection at 13 months, prompting high-resolution computerized tomography (HRCT) of the chest. He gradually deteriorated, eventually requiring ventilatory support; death occurred at age 15 months. This report illustrates the clinical heterogeneity of the syndrome. We review the theories about etiology and the recognized clinical findings in adults. Incidence may be higher than previously estimated, and tracheobronchomegaly (TBM) should be considered as a cause of respiratory failure and recurrent pneumonia in children where other investigations, including chest X-ray (CXR), are normal. A chest HRCT (cHRCT) scan and bronchoscopy are usually diagnostic.

[Specific notch in early expiration region of a flow-volume curve in a case of Mounier-Kuhn syndrome]

A 75-year-old man presented at our hospital for evaluation of a chronic cough and sputa. Radiographic examination showed enlargement of the trachea and main bronchi. On chest radiography, the transverse diameter of the trachea was 39 mm at the level of the third thoracic spine. On bronchoscopy, the trachea and main bronchi were dilated on inspiration and were completely collapsed on expiration. A 3-D CT examination showed the trachea and main bronchi dilated, and the cartilage of the trachea and bronchi distorted. In pulmonary function testing, this disorder is characterized by the appearance of a specific notch in the early phase of expiration on the flow-volume curve.

Tracheomegaly in association with rheumatoid arthritis

Herein we present a case of tracheomegaly seen in a patient with rheumatoid arthritis. To the authors' knowledge, and from a review of the literature, this combination has not been previously described.