[Histiocytosis X--a retrospective analysis of 40 cases with localized or disseminated disease].

A retrospective analysis of 40 cases with histiocytosis X was undertaken to find out the course of primarily localized disease, and the prognosis of children with initially disseminated disease. Bone lesions recurred in nine of 23 children with localized histiocytosis X. In eleven cases other organ manifestations occurred as well; in four cases without bone relapse. After an observation period of 1-14 3/12 years, nine of 22 children in remission suffer from long-term sequelae like diabetes insipidus, convulsion, extrahypothalamic CNS-disease, orthopedic disability, growth retardation, dystrophia adiposogenitalis , and chronic headache. Four of 17 children with disseminated histiocytosis X died. Our results and others from the literature indicate various risk factors to be prognostically significant. 1) age less than 2 years 2) involvement of spleen and/or lung 3) elevated Lahey-score 4) dysfunction of the hematopoietic system, liver, and/or lung 5) histologic feature resembling malignant type 6) no response to therapy 7) severely affected general health. These factors can be evaluated initially. Considering our own experiences and some risk factors we suggest the definition of four risk groups: 1.) localized histiocytosis X of bone, lymph nodes or skin; 2.) disseminated histiocytosis X with benign histologic type and Lahey-score of one or two; 3.) Lahey-score of 3-8; 4.) disseminated histiocytosis X with dysfunction of certain organ systems and/or malignant histology.