Brain 18-FDG PET scan in central nervous system langerhans cell histiocytosis.

We used positron emission tomography (PET) to characterize cerebral metabolism in 7 patients (serial examinations in 2 patients) with central nervous system disease in Langerhans cell histiocytosis (CNS-LCH) who had neuroendocrine abnormalities (n = 7), neuropsychiatric disabilities (n = 3), and CNS degenerative disease (n = 1). The PET scan alterations occurred at localizations with known CNS-LCH disease. The PET scans revealed areas where the metabolism and function were altered in 6 of the 7 patients studied, with either an increased or a decreased metabolism (uptake of glucose).