Langerhans cell histiocytosis in children: A retrospective case series of 126 cases.

BACKGROUND/OBJECTIVES Langerhans cell histiocytosis (LCH), a rare neoplasm of hematopoietic myeloid precursor cells, is clinically characterized by spontaneously resolving lesions to a progressive life-threatening multisystem disorder. Diagnosing LCH in children is challenging as it mimics other skin disorders. This study describes the varied clinical presentation and disease course in children less than 18 years diagnosed with LCH. METHODS We performed a retrospective observational study of all cases diagnosed with LCH presenting to a children's hospital in the last 26 years. Data on history, cutaneous and systemic examination, and laboratory evaluation performed, were recorded. RESULTS A total of 126 children diagnosed with LCH were included in the study. There were 68% cases limited only to skin, and 32% children with multisystem involvement at the initial presentation. Scaly papules were the most common morphologic finding in skin. The skeletal system was the second most common organ system to be affected. Failure to thrive was a common symptom. Progression of skin to systemic involvement was seen in 27.9%. In 76.7%, skin lesions cleared over a period of 2 to 4 years. Complete remission was seen in 56.9% of children over a period of 3 to 7 years, while 8.1% children died of complicationsand 31.8% were lost to follow-up. CONCLUSIONS Long-term follow-up in this study has shown cutaneous LCH without systemic involvement has a good prognosis. Skin involvement,along with failure to thrive, was the most common clinical presentation in our study. The skeletal system was the second most common organ system involved.