a form of histiocytosis with yellowish lesions.
juvenile xanthogranuloma. this is a common and completely benign cutaneous nodule. typically, a juvenile xanthogranuloma is firm and dome-shaped. at first, the lesion is reddish, but develops a fairly typical orangebrown hue over time. most juvenile xanthogranulomas are located on the head or neck, as pictured in these two infants, but the lesions sometimes occur on the trunk or extremities. they may be present at birth, but most develop during the first year of life. juvenile xanthogranuloma is not associated with abnormalities in serum cholesterol or triglycerides, and the individual lesions undergo spontaneous involution, usually over a period of 1–2 years. a diagnostic biopsy analysis is sometimes needed, but surgical intervention beyond this is certainly not required. multiple juvenile xanthogranulomas on the skin may be accompanied by intraocular lesions. for this reason, the physician must pay careful attention to the examination of the eyes. medicinenet.com
classifying histiocytic disorders is difficult (see table histiocytic disorders) and has changed over time as an understanding of the biology of these cells has evolved. langerhans cell histiocytosis is the most common histiocytic disorder. there are other rare histiocytic disorders such as erdheim-chester disease and juvenile xanthogranuloma, some of which are now considered variants of langerhans cell histiocytosis. merckmanuals.com