Cerebral histiocytic lymphoma presenting with loss of weight.

An adult man presented with loss of weight and this progressed over several months before the appearance of signs of neurologic disease. Autopsy showed histiocytic lymphoma with extensive meningeal spread and dense infiltration of the hypothalamus. This diencephalic syndrome has been reported with cerebral tumor, leukemia, encephalitis lethargica, multiple sclerosis, and Alzheimer disease, CT of the brain and examination of the CSF may be helpful in diagnosis.