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Langerhans' cell histiocytosis (histiocytosis X): experience at the Children's Hospital of Philadelphia, 1970-1984.

Sixty-four patients with biopsy-proven Langerhans' cell histiocytosis (LCH, formerly designated as histiocytosis X) were managed at the Children's Hospital of Philadelphia from 1970 through 1984. Their median age was 3 yr (range, 0.1-22 yr). Thirty-three patients had localized lesions affecting a bone (27) or soft-tissue region (6). Twenty-two patients had multifocal disease affecting bones (17) or soft, nonosseous tissues (5). None of these patients had evidence of dysfunction of liver or lungs, and none had abnormal peripheral blood cell counts. The remaining nine patients had multifocal LCH plus dysfunction of liver or lungs (6) or abnormal blood counts (3). Treatment consisted primarily of surgical excision for patients with localized lesions and of drug therapy with or without irradiation and surgery for those with multifocal disease. Recurrence was infrequent (7%) in those with localized LCH, and all survived. Recurrence was frequent (74%) in those with multifocal LCH but without organ dysfunction or abnormal blood counts, but 21 of the 22 survived. By contrast, only three of the nine patients with organ dysfunction or abnormal blood counts survived. Thus organ dysfunction and abnormal blood counts at diagnosis emerged as the major adverse prognostic factors in children with LCH.