Rare-26. gliomatosis, to be or not to cerebri: an evaluation of host systemic immune factors that potentially predispose to diffuse infiltrative glioma patterns

Gliomatosis cerebri (GC) has been debated as a pathologic entity sui generis versus a simple imaging and histologic pattern. Whereas the World Health Organization (WHO) 2000 classification considered GC a distinct tumor entity, WHO 2007 downgraded GC to a diffuse glioma pattern of extensive CNS infiltration, mostly of astrocytic phenotype involving at least three cerebral lobes, and the WHO 2016 further downgraded GC by removing the chapter. Tumors with distinctive GC presentation have been proven to be molecularly heterogeneous; however, paucity of data defining the pathophysiology and genetic driver(s) of this extensive diffuse infiltration pattern beleaguers the clinicians’ treatment planning. The GC literature is limited to retrospective studies, expert reviews, and one ongoing phase II trial evaluating the use of dose-dense temozolomide. We reviewed 32 primary GC cases (2011-2014) to compare patient demographic, clinical, radiographic, molecular, tissue pathology, and survival data. We found the major histologic phenotype was diffuse astrocytoma WHO grades II–IV (n=28, 87%; grade II, n=10; grade III, n=8; and grade IV, n=10), and noted predominant temporal lobe involvement (n=25, 78%). Treatment varied depending on histologic grade. The overall survival for astrocytic vs oligodendroglial tumors was 11.5 months versus 42 months respectively. Patients with IDH mutation (n=6) fared better, with median survival >33 months, consistent with previo...
Source: Neuro-Oncology - Category: Cancer & Oncology Authors: Tags: RARE TUMORS Source Type: research