A LATE PRESENTATION OF MOUNIER-KUHN SYNDROME IN A 71-YEAR-OLD MAN

Abstract

TOPIC: Imaging TYPE: Fellow Case Reports INTRODUCTION: Mounier-Kuhn Syndrome (MKS) is a rare congenital entity characterized by abnormal enlargement of the trachea and main bronchi. MKS was first described at autopsy in 1897 by Czyhlarz. Mounier-Kuhn described the association of endoscopic and radiographic appearance of the enlarged airways in 1932. CASE PRESENTATION: A 71-year-old male, former smoker, with a past medical history of an intellectual disability, severe malnutrition, weight loss, chronic decubitus ulcers, on 2 L. home oxygen therapy and multiple prior episodes of pneumonia, presented to the emergency department by Emergency Medical Service (EMS) after experiencing cardiac arrest at home. Earlier in the day, the patient was reported to be intermittently hypoxic with desaturations to the 70s. After lunch, he suddenly became unresponsive. He had bystander cardiopulmonary resuscitation (CPR) for 10 minutes until EMS arrived. Return of spontaneous circulation (ROSC) was achieved, but he arrested again after intubation, with additional 7 minutes of CPR prior to achieving ROSC. At the hospital, the patient was hypotensive and required intravenous fluids and multiple vasopressor support. A chest x-ray reported a right-sided pneumonia. He was treated with antibiotics. CTA of the chest showed enlargement of the trachea and bilateral bronchi with bronchiectasis, consistent with MKS. Also showed a pneumomediastinum and a small pneumothorax on the right. Pulmonary embolism (PE) was ruled out. Bronchoalveolar lavage showed Methicillin resistance Staphylococcus aureus (MRSA) and antibiotics were de-escalated. He eventually required a tracheostomy and discharged to LTAC. DISCUSSION: MKS is an entity more common in males with 8:1 predominance. The prevalence in the population has not been determined yet but a review found 360 cases published until 2016. The mean age of diagnosis is 53.9 years.The diagnosis of MKS is made when the transverse and sagittal diameters of the trachea exceed 25 mm and 27 mm in men and 21 mm and 23 mm in women, respectively; or when the transverse diameters of the right and left main bronchi exceed 21.1 mm and 18.4 mm in men and 19.8mm and 17.4 mm in women, respectively. There has been no correlation between increasing age and increasing tracheal diameter.Bronchiectasis, tracheal diverticulosis and tracheobronchial dyskinesia have been associated frequently. The most common complains are cough, dyspnea and recurrent respiratory infections.This case was unfortunately missed by many providers and incidentally found in post cardiac arrest admission. CONCLUSIONS: Providers should recognize the enlarge airways on chest imaging and the diagnosis is easily made once obtaining measurements. REFERENCE #1: Krustins E, Kravale Z, Buls A. Mounier-Kuhn syndrome or congenital tracheobronchomegaly: a literature review. Respir Med. 2013;107(12):1822-1828. doi:10.1016/j.rmed.2013.08.042. REFERENCE #2: Menon B, Aggarwal B, Iqbal A. Mounier-Kuhn syndrome: report of 8 cases of tracheobronchomegaly with associated complications. South Med J. 2008;101(1):83-87. doi:10.1097/SMJ.0b013e31815d4259 REFERENCE #3: Krustins E. Mounier-Kuhn syndrome: a systematic analysis of 128 cases published within last 25 years. Clin Respir J. 2016;10(1):3-10. doi:10.1111/crj.12192 DISCLOSURES: no disclosure on file for Frank Biscardi; No relevant relationships by Moises Cossio, source=Web Response No relevant relationships by Fernando Fuentes, source=Web Response