Meningeal and brainstem infiltration by a malignant mesothelioma.

Malignant mesothelioma is an uncommon neoplasia which primarily involves the pleura or peritoneum. Central nervous system involvement is rare. A rare presentation of metastatic pleural mesothelioma, which had infiltrated the meninges and brainstem, is described. The patient presented with diplopia following a 2-week history of malaise, myalgia, mild headache and diarrhoea. Clinical examination found global areflexia, cerebellar ataxia and bilateral sixth nerve palsies. Differential diagnoses included the Miller-Fisher variant of Guillain-Barre syndrome, malignant meningitis and infectious meningitis. The patient was treated with immunoglobulins, plasmaphoresis and corticosteroids; however, he deteriorated and died 31 days after admission. Retrospective examination of the MRI of the brain found diffuse low attenuation changes within the pons and cerebral peduncles. Postmortem examination favoured a diagnosis of an early sarcomatoid malignant mesothelioma of pleural origin with leptomeningeal metastatic deposits.