Clinical, Histopathologic, and Magnetic Resonance Imaging (MRI) Findings in Gliomatosis Cerebri (P03.139)

Abstract

Objective: To characterize clinical, histopathologic, and radiologic features in 32 patients with gliomatosis cerebri (GC). Background GC is a rare primary tumor of the central nervous system, characterized by diffuse neoplastic glial cell infiltration of more than two cerebral lobes and relative preservation of the surrounding brain architecture. Although primarily astrocytic in origin, cases with oligodendroglial and mixed oligoastrocytic features have been described. Radiologically, GC is defined by no or minimal contrast enhancement on magnetic resonance imaging (MRI). Design/Methods: We identified 32 subjects from the neuroradiology and neuro-oncology database at the Massachusetts General Hospital who met the diagnostic criteria of GC. Clinical, histopathologic, and imaging characteristics were assessed. Results: Most common clinical symptoms at presentation were seizures (63%), cognitive dysfunction (28%) and headaches (16%). Tumors were classified as WHO grade II and WHO grade III with equal distribution, and most commonly were diagnosed as astrocytomas (n=20), oligodendrogliomas (n=4), and mixed oligoastrocytomas (n=3). Forty-four percent had bihemispheric T2/FLAIR hyperintensity on MRI, with frequent involvement of the temporal (n=31) and frontal (n=25) lobes as well as the subventricular zone (n=24). Treatment involved surgery (n=13), radiation (n=15), chemotherapy (n=26), and combined chemo-radiation (n=10). Median overall survival (OS) for all patients was 32 months from the time of radiologic diagnosis (ranging from 20 days to 231 months). Median time to progression after the first (TTP1), and second (TTP2) treatment regimen were 15 and 9 months, respectively. Conclusions: Patients with GC present with heterogeneous clinical, pathologic, and imaging findings. Some patients demonstrate prolonged overall survival of more than 10 years suggesting subpopulations of GC patients with significantly better prognosis. Further detailed characterization of molecular and histopathological features of GC and advanced neuroimaging techniques may help to identify distinct subgroups of GC and guide further treatment decisions. Supported by: The American Brain Tumor Association and the American Academy of Neurology Foundation. Disclosure: Dr. Ly has nothing to disclose. Dr. Pine has nothing to disclose. Dr. Stemmer-Rachamimov has nothing to disclose. Dr. Hochberg has nothing to disclose. Dr. Dietrich has nothing to disclose.