Glioblastoma Multiforme (left parietal)


Image 1

Clinical History: 
A 57 year old man presents with a mass lesion on CT, with MR performed for differential diagnosis and better delineation of the lesion.

Glioblastoma Multiforme

MR Technique: 
2D T2 weighted fast spin echo and post-contrast T1 weighted gradient echo scans are illustrated. The scans were obtained at 3 T, on a Siemens Verio MR unit. Slice thickness was 4 mm, with scan times of 2:22 and 2:08 respectively. 17 ml of a macrocyclic gadolinium chelate was administered intravenously, given on a weight basis (0.1 mmol/kg, standard single dose), for contrast enhancement.

Imaging Findings:
A large mass lesion is noted in the left parietal lobe. There is extensive associated vasogenic edema, best seen as abnormal high signal intensity on the fast spin echo T2-weighted scan. There is obliteration of adjacent sulci, due to mass effect. There is irregular, peripheral enhancement, with a large central nonenhancing region, most consistent with fluid or necrotic tissue. A small second lesion, separated slightly from the dominant mass, is seen just anteriorly. Not shown is the level of the splenium, which demonstrated abnormal increased signal intensity extending across the midline on both FLAIR and T2-weighted scans.
The imaging findings demonstrated by the dominant mass lesion are most consistent with a glioblastoma. Although other high grade tumors could be considered, these are much less likely. Glioblastomas can be multicentric or multifocal, thus a small daughter lesion as demonstrated is not unusual. The abnormal high signal intensity on T2 weighted scans within the splenium is consistent with tumor spread, with the corpus callosum consisting of very compact white matter tracts. Vasogenic edema does not typically cross the corpus callosum. It is important to note that only the high grade portions of the lesion will enhance, and that any area of abnormal signal intensity may (and likely) contains tumor cells. Histologically these lesions extend well beyond any abnormality depicted on MR, whether due to abnormal signal intensity or contrast enhancement.