Gangliocytoma of the pineal body. A case report and review of the literature.

Ganglion cell tumours are mostly seen in children and young people, but they are extremely rare, accounting for 0.1-0.5% of all brain tumours. It usually occurs in the floor of the third ventricle and the temporal lobe. Recently we have experienced a pineal gangliocytoma, probably the first ever seen in Japan and the fourth case in the world, and have succeeded in a total removal of it. The case concerns a 51-year-old man who suffered from intermittent blurred vision and headache of 3 years' duration. CT showed, together with severe hydrocephalus, positive contrast medium enhancement and a somewhat irregular but sharply circumscribed high density lesion suggestive of a meningioma. But the brain scintiscan revealed a badly and irregularly demarcated region of warm activity and having little change with time mainly in the pineal region, which was strongly suspicious of gliomas. Hence this scan was thought to be important in diagnosing this tumour. As an operative procedure, biparieto-occipital craniotomy was successfully performed in the "sea lion" position to remove the tumour totally. Pathological findings indicated a mixture of dispersion and concentration of giant cells possessing prominent nucleoli, abundant chromatin and a prominent nucleus or several nuclei of varying sizes and process-like cell bodies polygonal or irregular in shape. GFAP stain showing no glial fibres and the tumour was thought to be a gangliocytoma.