Langerhans cell histiocytosis: A retrospective analysis in a K orean tertiary hospital from 2003 to 2012

Epidemiological study of Langerhans cell histiocytosis ( LCH ) has been limited due to its rarity and multisystemic involvement. The aim of this study was to investigate the epidemiological features of LCH via the clinical data warehouse ( CDW ). Clinical data of 30 LCH patients from the all departments of a tertiary referral hospital between 2003 and 2012 were analyzed retrospectively by searching the CDW . The male‐to‐female ratio was 2.8:1. The age of onset ranged 7 days to 57 years with a median of 13 years. Of the patients, 36.7% presented initial symptoms before the age of 10 years. The involved organs at diagnosis were: bone (66.7%), skin (16.7%), lungs (13.3%) and lymph node (3.3%). For all of the 30 cases, there were 31 disease sites because of a single case of multisystemic disease involving both skin and bone. Of the 96.7% of patients with single‐system disease, 69.0% had bony involvement. This study elucidated the clinical features of LCH from all the departments of a tertiary hospital via the CDW , which suggests a potential role of the CDW as a new epidemiological approach for rare diseases.