Cerebromeningeal haemophagocytic lymphohistiocytosis.

We describe 3 children with a progressive encephalopathy that was characterised by irritability, convulsions, cranial nerve palsies, ataxia, nystagmus, walking difficulties, delayed psychomotor development, hemiplegia/tetraplegia, visual disturbance, vomiting, neck stiffness, and non-specific signs of raised intracranial pressure. A final diagnosis was made in all 3 patients from necropsy material. The clinical features were ascribed to multiple inflammatory, predominantly lymphocytic, reactions and raised intracranial pressure. This condition is an atypical form of haemophagocytic lymphohistiocytosis, which normally presents with fever, hepatosplenomegaly, and cytopenias. By contrast, the disease pattern in our 3 children was dominated by cerebromeningeal involvement, which can precede the typical systemic symptoms of haemophagocytic lymphohistiocytosis. An awareness of this condition is important because treatments are available.