Histiocytosis X.

A patient with histiocytosis X had nonhealing mouth lesions. Evaluation revealed diabetes insipidus and numerous bony lesions. Electron microscopy of the mouth lesions and lymph nodes did not indicate Langerhans cells, which have frequently been described as occurring in histiocytosis X. A survey of 59 patients examined during a 20-year period at UCLA reported the presence of oral lesions in 42% of the cases and confirmed the occurrence of a wide range of clinical patterns and variations in the course of the disease.