The multiple faces of Langerhans cell histiocytosis in childhood: A gentle reminder.

Langerhans cell histiocytosis (LCH) is a rare hematologic disorder that results from the clonal multiplication and accumulation of immature dendritic Langerhans cells. Its reported incidence rate varies, but is considered to be 2.6-8.9 per million children who are <15 years of age each year. It may affect any system or organ. The present study reported 4 pediatric LCH cases in order to highlight the heterogeneity of the initial presentation, and the pitfalls that may mislead clinicians and delay diagnosis. The clinical features, as well as the pathognomonic imaging, pathology findings and treatment options were presented. LCH may be rare, but it should always be included in the differential diagnosis of persistent eczema, unexplained skin lesions, diabetes insipidus and persistent bone pain, among others. While the debate on pathogenesis and treatment is ongoing, high index of suspicion among pediatricians, pediatric oncologists and other specialists (pathologists, dermatologists, orthopaedic surgeons, general practitioners or family physicians) is essential for early diagnosis, and optimal outcome.