Collision Occurrence of Meningioma and Astrocytoma: A Case Report and Literature Review.

A case of collision tumors occurring between two distinct primary brain tumors is reported. A 61-year-old female without history of radiotherapy or phakomatosis presented with progressive ly increasing headache and left hemiparesis. Investigation revealed a meningioma and a Grade II astrocytoma in the right frontal lobe. Simultaneous development of a meningioma and a low-grade glioma at adjacent sites is extremely rare. This is the third case reported in the literature. Some hypotheses are proposed to explain this phenomenon but most likely represent a coincidental event.