Familial Lymphohistiocytosis of the Nervous System

Four children in a family had a progressive neurologic disease characterized by diffuse lymphohistiocytic infiltrations of the central nervous system (CNS) in association with multiple foci of parenchymatous destruction. The age range was 15 months to 12 years. The clinical features, although variable, comprised seizures, spastic weakness of limbs, and ataxia. The cerebrospinal fluid showed pleocytosis and increased protein. Histopathologically the disorder resembled what has been called familial hemophagocytic reticulosis, or familial erythrophagocytic lymphohistiocytosis, but unlike those disorders, was largely confined to the CNS. The cause and pathogenesis remain unknown. A genetically-determined atypical response to an undisclosed infection is possible.