Neuroimaging characteristics in subgroup of GBMs with p53 overexpression

Glioblastoma multiforme (GBM) is a heterogeneous group of tumors, and neuroimaging characteristics have not been well-defined in molecular subgroups. Eighty-five patients with GBM were analyzed regarding imaging characteristics and correlation to p53 expression. The p53 positivity was graded according to percentage of positive cells (Grade 0, for < 10%; Grade 1, for <25%; Grade 2, for 26-50%; Grade 3, for >50% labeled cells). Imaging characteristics evaluated in the preoperative MRI were location and number of lesions, dimensions of enhancing lesion and of surrounding edema, mass effect, tumor borders, enhancement pattern after intravenous contrast administration, and tumor necrosis. Eighteen tumors had p53 expression >50% in immunohistochemical staining. Preoperative MRI of patients harboring those tumors with high p53 positivity revealed typical lesions with ring enhancement pattern and well-defined borders in T1-weighted images with contrast, and they were significantly different from other groups of p53 expression. There was no difference in terms of location and number of the lesions, dimensions of enhancing lesion and surrounding edema, mass effect, and the tumor necrosis between four different groups of p53 expression. A special subgroup of GBMs with p53 overexpression has ring enhancement pattern and well-defined border on MRI that may be influential in preoperative planning and postoperative management of adjunct therapy.