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.