Modern imaging methods for the assessment of Langerhans' cell histiocytosis-associated neurodegenerative syndrome: case report.

Langerhans' cell histiocytosis-associated neurodegenerative syndrome is an enigmatic manifestation, most often localized in the cerebellum and the basal ganglia. Its pathophysiologic basis is poorly understood, and effective treatment strategies are currently missing. Modern imaging modalities offer the possibility of shedding further light on this puzzling disease in a noninvasive way. We report on a 12-year-old boy with a Langerhans' cell histiocytosis-associated neurodegenerative syndrome who underwent a thorough evaluation with different modern imaging methods in addition to routine brain magnetic resonance imaging (MRI) to analyze their informative value for this condition. Additional imaging included positron emission tomography using [18F]fluorodeoxyglucose (FDG-PET), single photon emission computed tomography using [123I]2beta-carbomethoxy-3beta-(4-iodophenyl)tropane and [123I]iodobenzamide, and magnetic resonance spectroscopy. The potential relevance of each method for neurodegenerative Langerhans' cell histiocytosis is discussed based on the results obtained, and a review of the literature is made. The case underlines the fact that MRI undoubtedly possesses the major role in the diagnostic evaluation and monitoring of Langerhans' cell histiocytosis-associated neurodegenerative syndrome. FDG-PET and magnetic resonance spectroscopy findings were in good correlation with the MRI results. In particular, magnetic resonance spectroscopy could provide a valuable diagnostic tool in addition to MRI in the early detection and evaluation of the neurodegenerative component of this disease.