This tumor could possibly be 50 years old

Ganglioglioma, WHO grade I

A 70-year-old gentleman presents with a temporal lobe mass. He was diagnosed with a seizure disorder way back when he was 20 years old, and has been on Dilantin since then. Over all these intervening years, he never underwent imaging -- until now. Breakthrough seizures prompted an MRI which showed a well-circumscribed solid and cystic mass. In retrospect, this indolent tumor may well have been present for decades.