Diffuse Encephalopathy Associated with Isolated Cerebral Langerhans Cell Histiocytosis

Abstract Background Langerhans cell histiocytosis is a rare disease of the monocyte–macrophage system. Abnormalities of the hypothalamic–pituitary region are common in individuals with central nervous system involvement. Patient Description This six-year-old boy developed rapidly progressive aggressive behavior, central diabetes insipidus, and repeated complex partial seizures. Magnetic resonance imaging revealed a diffuse leukoencephalopathy-like pattern and numerous infratentorial and supratentorial granulomatous nodules in the brain parenchyma along with infundibular and hypothalamic mass lesions. Stereotactic serial biopsies enabled histopathologic and immunohistochemical diagnosis of Langerhans cell histiocytosis. Conclusions Similar MRI findings have rarely been described in the literature. These findings represent part of the broad neuroradiological spectrum of Langerhans cell histiocytosis of the nervous system in children.