Favored gyral sites of supratentorial astrocytic tumors

ABSTRACT

It is well known that the predilective sites of extrinsic tumors (meningiomas, chordomas, etc) are at the skull base and along the calvarium. Although intrinsic tumors or glial tumors have also been seen to have anatomic and functional predilective sites within the central nervous system, these have not been well documented. We conducted this study to investigate if supratentorial astrocytic tumors have a predilection for specifi c gyri. We investigated the clinical and radiological records of 60 successive patients who had been operated on at our institution and had had histologically confi rmed supratentorial astrocytic tumors (36 males, 24 females, mean age: 52 years). Coronal sections were selected from the pre-operative contrast enhanced T1-weighted magnetic resonance imaging (MRI). The labeling of gyral areas for analysis of MRI was done using Yaşargil’s method. Additional information obtained from 3-dimensional MRI and surgical fi ndings was taken into account when it was diffi cult to distinguish the specifi c gyrus in which the tumor was located. The middle portions of the frontal gyri, insular gyri and the supramarginal gyrus and its surroundings were among the most common locations for the development of tumors. Interestingly, with the exception of one case, none of the tumors was situated in the precentral or postcentral gyri. It seems that supratentorial astrocytic tumors have a predilection for specifi c gyri and disfavor some other gyri. This cannot be explained simply by the different sizes of the cerebral lobes. A classical lobar concept of cerebral anatomy may lead to a misunderstanding of cerebral pathophysiology.