AN UNUSUAL FORM OF LOCALIZED PAPULONODULAR CUTANEOUS HISTIOCYTOSIS INA 6-MONTH-OLD BOY

We report a 6-month-old boy with an unusual form of cutaneous histiocy tosis. The lesions were noticed shortly after birth, and there was no evidence of systemic disease. This histiocytic disorder could not be c lassified according to the Histiocyte Society classification, and was therefore designated an 'unclassified' group II histiocytic disorder. The clinical picture was characterized by dark-red papulonodules with a tendency to coalesce into plaques. Histologically, the infiltrate wa s characterized by non-epidermotropic histiocytes showing varying degr ees of differentiation, eosinophils and lymphocytes, and by the absenc e of foamy cells and Touton giant cells, As a most conspicuous feature , electron microscopic examination revealed laminated dense bodies, wh ereas Birbeck granules and comma-shaped bodies were absent. This furth er distinguished this uncommon variant from the well-known class II hi stiocytoses. During a 6-month follow-up period all the lesions showed marked regression.