NCIt definition : A benign histiocytic tumor that usually arises from the skin and occurs during childhood;
it is distinct from Langerhans cell histiocytosis. It is characterized by the presence
of lipid-laden, foamy histiocytes and Touton-type giant cells in the dermis. The lesions
usually develop during infancy. While the majority of cases arise from the skin, it
can rarely also arise from extracutaneous sites including the eye, ocular adnexa,
oral cavity, paranasal sinuses, and ear. It is sometimes associated with deep soft
tissues nodules.;
Alternative definition : NICHD: A macrophage disorder that occurs during childhood; it is distinct from Langerhans
cell histiocytosis, and is characterized by cutaneous papules and nodules (most often
in the head and neck).;