A case of S100-positive atypical juvenile xanthogranuloma: a longitudinal observation and review of the literature / 中华皮肤科杂志

ABSTRACT

A 3-year-old boy presented with a 3-month history of brown-yellow papules scattered on the trunk.The first skin biopsy showed a dermal infiltrate of many mononuclear histiocytes,eosinophilic granulocytes and a small number of lymphocytes.Immunohistochemical examination of the lesions demonstrated positive reactions with anti-CD68,-S100 and-CD1a (partial) antibodies.After the biopsy,the skin lesions gradually turned dark and partially regressed leaving hyperpigmentation,but new lesions continuously appeared.Four months later,a second biopsy was performed,and showed a dermal infiltrate of histiocytes with eosinophilic granulocytes and a few multinucleated giant cells.Immunohistochemistry showed that the histiocytes stained positive for CD68,but negative for S100 and CD1a.Based on the above findings,the patient was diagnosed with juvenile xanthogranuloma.