Histiocytosis X of the head and neck in a pediatric population.

Despite an extensive literature, histiocytosis X is still a poorly understood disease and the origin remains unknown. To study the impact of recent therapeutic and diagnostic advances on this disease, 28 cases of histiocytosis X treated at Children's Hospital of Los Angeles, Calif, from 1976 through 1987 were reviewed. A classification system was developed that accurately described the clinical outcome in our patients. Type patients (n = 7) had monostotic disease, and type 2 patients (n = 15) had multiple tissue sites other than the viscera. The latter type was further divided into types 2A and 2B, depending on whether lesions were solely osseous (type 2A [n = 8]) or if soft-tissue sites were involved (type 2B [n = 7]). Type 3 patients (n = 6) had disseminated disease at the time of presentation, as defined by visceral involvement other than the liver. Type 1 patients were usually treated by surgical curettage alone and had an excellent prognosis. Type 2A patients required either surgery or radiation for symptomatic lesions. Type 2B patients were treated similarly. In addition, Type 2B patients received chemotherapy, a practice that is intensively debated in the literature. All the Type 2 patients survived with varying morbidity. Type 3 patients were all treated with chemotherapy but none of them survived. The majority of patients with histiocytosis X had otolaryngologic manifestations ranging from bony lesions to infectious complications. To conclude, the term histiocytosis X should be maintained to describe a spectrum of diseases. A simple classification system with three divisions gives reliable prognostic and therapeutic guidelines.