A DESCRIPTIVE ANALYSIS OF GLIOMATOSIS CEREBRI CASES, COMPARED ACCORDING TO IDH STATUS

Abstract Gliomatosis cerebri (GC) is a controversial entity no longer recognized as a histopathologic-defined diagnosis, characterized by diffuse, commonly bilateral infiltration of cerebral hemispheres. The purpose of this report is to describe clinical, imaging, patient-reported outcomes (PRO’s) and pathologic characteristics of clinically-defined cases from a large natural history study cohort (N=769). Of 19 patients, 10 male, 16 white, mean age at diagnosis 43 (19-70), seventeen presented as primary GC, while 2 developed GC after treatment. Ten patients were IDH-WT, 7 IDH-M, and 2 IDH undetermined. The majority (7/10) IDH-WT patients presented acutely (5 with seizures), whereas, 3 had a protracted presentation of 2 weeks-3months with 6/10 having enhancing tumors and 8/10 undergoing biopsy only. On histopathologic review, 4 were anaplastic astrocytoma (AA), 3 GBMs, 2 grade II astrocytoma, and 1 histone-mutated glioma. Nearly all (9/10) IDH-WT patients received radiation with concurrent and adjuvant temozolomide. 7/10 IDH-WT patients had a survival of only 1.5yrs or less from diagnosis. Of the 7 IDH-M patients, 4 had protracted presentations of 1 month-5 years. 6/7 had non-enhancing tumors at presentation. 4 had biopsy only and 3 underwent partial resection. 3 were AA, 2 grade II astrocytoma, 1 grade II oligodendroglioma, and 1 grade IV astrocytoma. 3/7 received radiation with concurrent and adjuvant temozolomide, 3/7 chemotherapy alone, and 1 RT alone. All 7 IDH-M patients survived 3+ years from diagnosis (range 3-10+ yrs). Both patients who developed GC later, were IDH-M, with prolonged survival (3.5yrs and the other still alive 10+yrs). PRO's at time of last clinical assessment revealed GC patients to be highly symptomatic with mean overall symptom burden, depression, and anxiety higher than our overall glioma population. GC patients have a varied clinical course mandating further investigation to enable better prognostic definition to refine treatments based on the varying clinical and molecular characteristics.