The hippocampal fissure is a fetal sulcus that is normally closed except for the medially located portion[^1]. Hippocampal sulcus remnant cysts, also referred to as hippocampal cavities, are residual cysts measuring approximately 1-2mm[^2] that are attributable to incomplete closure of the hippocampal fissure and can be visualized on MRI imaging[^1].
Epidemiology
Hippocampal sulcus remnant cysts can be observed in approximately 10-40% of the adult population[^1] [^2].
Imaging
Hippocampal sulcus remnant cysts can be optimally visualized on MRI.
