Large isthmus of the cingulate gyrus: an unusual anatomical variation simulating tumor

The isthmus of the cingulate gyrus connects the cingulate gyrus to the parahippocampal gyrus. This isthmus demonstrates variable morphological appearances ranging from normal to prominent, and very prominent types. One unusual variety is an apparently large isthmus with a potential to be misinterpreted as a tumor, which is the main topic of this paper.