Pulmonary transplantation in Mounier-Kuhn syndrome: a case report

Early manifestation of ARDS in COVID-19 infection in a 51- year-old man affected by Mounier-Kuhn syndrome

A 51-year-old man known to be affected by Mounier-Kuhn syndrome (MKS). presented to Accident & Emergecy (A&E) with fever, dyspnea and deterioration of his chronic coughs. Increased diameters of his trachea (39 mm), right (30 mm) and left (26 mm) main bronchi were revealed by chest computerized tomography (CT) scan. CT scan showed also ground-glass opacities (GGO) and bronchiectasis in the mid and lower zones of both lungs. COIVD-19 infection was eventually confirmed by RT-PCR. A severe form of COVID-19 could occur even in the early stages of the disease in presence of underlying co-morbidities including MKS, which increases the susceptibility to more recurrent and severe respiratory infections.

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.

Tracheobronchomegaly associated with laryngo-tracheal amyloidosis: First case report

Tracheobronchomegaly (TBM) is a rare enlargement of the tracheal cartilage, also known as Mounier-Kuhn syndrome (MKS). Here, we describe an unusual case of acquired TBM in an adult, caused by amyloid regeneration and associated tracheal weakening, rather than by MKS. CT scan and fiberscopic examination of a 55-year-old woman suffering from severe dyspnea revealed TBM and subglottic stenosis, which was caused by deposition of amyloid tissue. We performed a tracheostomy and vaporized the subglottic stenosis with a CO2 laser, after which we installed a silicone T-tube. After the first operation, re-stenosis occurred, and the procedure was repeated; stenosis was subsequently cured and the dyspnea disappeared, after which the tracheostomy could be closed. This is the first report of adult TBM associated with amyloid deposition in the subglottis and trachea. This diagnosis is very difficult, as amyloid deposition in the trachea can have various clinical presentations.

Clinical-radiological, histological and genetic analyses in a lung transplant recipient with Mounier-Kuhn syndrome and end-stage chronic obstructive pulmonary disease

BACKGROUND AND AIMS

The Mounier-Kuhn syndrome (MKS) is a rare disease characterized by a pathological dilation of the trachea and the bronchial system. The etiology of the disorder remains elusive, but genetic alterations and degradation of elastic fibers are thought to be involved in the pathogenesis. No causative treatment is available although transplantation is an option for end-stage disease. Here, we describe a patient suffering from MKS who received a double lung transplant at our department.

METHODS

Since a familial clustering of MKS is discussed in the literature, we performed a chromosomal analysis and an array-comparative genomic hybridization (CGH) to search for genetic abnormalities. At the time of transplantation, we collected samples from the bronchi and performed hematoxylin and eosin (HE), Elastic von-Gieson (EVG) and immunohistochemical stains of the explanted MKS bronchus, a control bronchus and of the inflammatory infiltrates. Specimens of main bronchi from the donor lung harvested for transplant served as control. Bronchial smears were taken from both main bronchi of the recipient for microbiological cultures.

RESULTS

No genetic alterations could be found in chromosomal analysis and in array-CGH. Histological analysis revealed a strong reduction of elastic fibers in the submucosal connective tissue and a diffuse inflammatory infiltrate, mainly comprised of CD4+ cells. In addition, immunohistochemistry showed increased matrix metalloproteinases (MMPs) protein expression of MMP-1, 2, 3 and 9.

CONCLUSIONS

Based on our findings, we hypothesize that MKS is a chronic inflammatory disease characterized by an MMP-mediated degradation of submucosal elastic fibers.

Mounier-Kuhn syndrome or congenital tracheobronchomegaly: a literature review

Mounier-Kuhn syndrome or congenital tracheobronchomegaly is a chronic airway condition which for currently unknown reasons mostly affects males. It is commonly overlooked on conventional chest X-rays, and is considered to be rare, but the prevalence might be higher as commonly assumed. The hallmark of it is a dilatation of the main airways which frequently, but not always, causes marked, mainly respiratory, symptoms, and patients usually present with varying degrees of recurrent infections, breathlessness, haemoptysis, dyspnoea. Although at least 200 case reports have been published, there have been only a few attempts to review them, and none in the last 20 years. Due to the lack of clinical trials and wide variability of case-report format, a systematic review was deemed not feasible, therefore PubMed and Medline databases were searched using terms "Mounier-Kuhn syndrome", "tracheobronchomegaly", "tracheomegaly", and "bronchomegaly", without any time restrictions, to summarize currently known facts about the syndrome. To the authors' best knowledge, the result is currently the most comprehensive review of previously published literature about the congenital tracheobronchomegaly, and summarizes what's known about symptoms, prevalence, disease associations, and treatment options for this syndrome.

Mounier-Kuhn syndrome and bilateral vocal cord paralysis

Mounier-Kuhn syndrome is a rare disorder of unknown cause that is characterized by atrophy of the elastic and smooth muscle of the tracheobronchial tree leading to tracheobronchomegaly and bronchiectasis. The syndrome is likely underdiagnosed, because the patients usually present with common respiratory symptoms such as productive cough and usually labeled as chronic obstructive pulmonary disease. Diagnosis is established on the basis of radiologic findings. Association with bilateral vocal cord paralysis has not been described. Treatment is mainly supportive. Symptomatic patients may require endobronchial stenting if airway collapse is encountered. Here, we described a patient who presented with hoarseness and pneumonia. Further studies confirmed the diagnosis of Mounier-Kuhn syndrome with bilateral vocal cord paralysis.

[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.