Last Updated: September 30, 2018
Meningiomas originating from the tentorium cerebelli account for about 3% to 6% of all intracranial meningiomas and about 30% of the meningiomas found in the posterior fossa. Like other meningiomas, these tumors are most common among middle-aged women.
They can originate anywhere on the tentorium, with about half occurring laterally along the transverse sinus, one-quarter along the medial or free edge of the tentorium, and the remaining one-quarter split primarily between tumors of the central portion of the tentorium and those involving both the tentorium and the falx. A very small proportion of these tumors are peritorcular, encompassing the torcula herophili.
Tentorial meningiomas have been classified in a number of ways by different colleagues, but Yasargil’s system, the most relevant for surgical planning, classifies meningiomas by location along the tentorium. Yasargil noted anatomic differences among what he described as the “three rings of the tentorium”: the inner ring or free edge, the outer ring along the transverse sinus...