Histiocytic Diseases of Neonates: Langerhans Cell Histiocytosis, Rosai-Dorfman Disease, and Juvenile Xanthogranuloma.

Langerhans cell histiocytosis, Rosai-Dorfman disease, and juvenile xanthogranuloma may present at birth or any time afterward. Some patients have minimal skin or lymph node involvement, but others present with life-threatening pulmonary, hepatic, bone marrow, or central nervous system lesions. There is often a delay in diagnosis because of confusing overlap with more common neonatal diseases. Many treatment regimens have been applied to these diseases, but those directed at myeloid cells, such as cytarabine and clofarabine or mutation-targeting inhibitors, are gaining favor. This article provides information on the pathophysiology, clinical presentation, evaluation guidelines, and treatment of these uncommon tumors of neonates.