The temporal, occipital, and parietal lobes are divided by the parietooccipital fissure, an anatomical landmark. The temporal lobe is the most common location for gliomas. Although the parietooccipital fissure is placed right beyond the medial temporal lobe, nothing is known regarding its clinical importance in gliomas. The authors looked into the anatomical relationships between the parietooccipital fissure and posterior medial temporal gliomas to learn more about their radiological characteristics. The authors classified tumor invasion as being toward the parietal lobe, occipital lobe, isthmus of the cingulate gyrus, insula/basal ganglia, or splenium of the corpus callosum to clarify how to invade the surrounding structures. The fiber tractography flowing through the posterior medial temporal lobe was seen using DSI Studio.

There were 24 patients with posterior medial temporal gliomas found. In all cases, a parietooccipital fissure was present as an uninterrupted straight sulcus along the tumor’s posterior border. The invasion was in the parietal lobe for 13 cases, the occipital lobe in four cases, the isthmus of the cingulate gyrus in 19 points, the insula/basal ganglia in three patients, and the splenium of the corpus callosum in eight cases. Although the isthmus of the cingulate gyrus and the occipital lobe are both placed directly posterior to the posterior medial temporal lobe, the isthmus of the cingulate gyrus had a substantially bigger prevalence of invasion than the occipital lobe (p = 0.00030, McNemar test). 4 individuals had type A tumors and 20 patients had type D tumors, according to Schramm’s categorization for medial temporal tumors. The posterior border of the tumors was defined by the parietooccipital fissure, resulting in a distinct and identical radiological appearance. According to diffusion spectrum imaging (DSI) tractography, the fibers traveling through the posterior medial temporal lobe toward the occipital lobe had to detour laterally along the bottom of the parietooccipital fissure.

The invasion patterns of posterior medial temporal gliomas are equivalent, resulting in distinct radiological characteristics heavily influenced by the parietooccipital fissure. Awareness of the intricate infiltrating architecture of posterior medial temporal gliomas requires understanding the parietooccipital fissure.