Mitotically active juvenile xanthogranuloma.

Juvenile xanthogranuloma is a histiocytic inflammatory disorder capable of presenting different histologic patterns. The classic form consists of sheets of foamy histiocytes and numerous multinucleated Touton-type giant cells containing no to very few mitotic figures. Nonlipidized juvenile xanthogranuloma consists of a diffuse monomorphic histiocytic infiltrate and usually shows a slightly higher mitotic index. Histologic hematoxylin-eosin staining techniques were used after excision of a pink ulcerated nodule in a 2-year-old girl. Histopathologic examination showed a nonencapsulated cellular proliferation mainly occupying dermis, but extending into the subcutaneous tissue as well. Most of the cells were epithelioid histiocytes, but foamy and Touton giant cells were also evident. The most striking feature was the presence of a high number of mitotic figures, as many as 23 per 10 high-power fields. We present an unusual case of classic juvenile xanthogranuloma with areas similar to those found in the nonlipidized type and with a high mitotic index.