Segmental juvenile xanthogranuloma.

A 5-month-old boy had erythematous nodules over the left side of his trunk with a segmental arrangement since birth. Histopathologic examination revealed sheets of foamy histiocytes infiltrating the dermis and subcutaneous fat, admixed with multinucleated giant cells and lymphocytes, making this an unusual case of juvenile xanthogranuloma appearing in a segmental distribution.