Collateral eminence

The collateral eminence is an elongated swelling lying lateral to and parallel with the hippocampus.

It corresponds with the medial part of the collateral fissure, and its size depends on the depth and direction of this fissure.

It is continuous behind with a flattened triangular area, the trigonum collaterale, situated between the posterior and inferior cornua.

It is not always present.