OBJECTIVETo improve the recognition of the clinical presentation and radiologic manifestation of children with Langerhans cell histiocytosis (LCH) with pulmonary involvement.

METHODA retrospective analysis was conducted on children who presented with respiratory symptoms or abnormal lung radiologic findings, and finally diagnosed with LCH in Ward 2 of Divison of Respiratory Diseases, Beijing Children's Hospital during the last 4 years.

RESULTFourteen children (10 boys and 4 girls) were included in this study. Male to female ratio was 2.5: 1. The median age was 1.3 years. Pulmonary involvements were coexisted with other involved organs in all the patients, such as skin (10 cases, 71%), liver (8 cases, 57%), and bone involvement (7 cases, 50%). The most common symptoms were cough and fever (7 cases, 50%). Respiratory symptoms were nonspecific, and 3 children had no respiratory symptom but abnormal findings on lung high-resolution CT (HRCT). The most common HRCT finding was the coexistence of nodules and cysts (6 cases, 43%). Other findings include cysts only (5 cases, 36%), nodules only (1 case), and with neither nodule nor cyst (2 cases, 14%). Pneumothorax was found in 7% of children.

CONCLUSIONPulmonary involvement in children with LCH is easily misdiagnosed, and often coexisted with other involved tissues/organs such as skin and liver. Rash, which is easily missed in physical examination is very important for the diagnosis of LCH. The characteristic findings of lung HRCT (nodules and/or cysts) are helpful for diagnosis.