"Unusual brain stone": heavily calcified primary neoplasm with some features suggestive of angiocentric glioma.

This 40-year-old man presented with a 5-month history of progressive right-sided headache associated with visual blurring. He also had a history of epilepsy but had been seizure free with medication for the past 10 years. An initial CT scan of his brain performed 16 years previously had revealed a small area of calcification in the right parietal region. In the current presentation, he had a left-sided homonymous hemianopia but no other neurological deficits. A CT scan of his brain showed a much larger calcified, partly cystic lesion in the right parietal region. Because he was symptomatic, the lesion was excised and the cyst was drained. Histological examination of the excised tissue showed an unusual primary tumor that was difficult to classify but had some features of angiocentric glioma. The heavy calcification, mixed-density cell population, and regions with features of angiocentric glioma were most unusual. The patient remained asymptomatic 5 years after surgery, and follow-up scans did not show recurrence.