P12.04 * GLIOMATOSIS CEREBRI: IS THERE A ROLE FOR SURGERY OTHER THAN BIOPSY?

Abstract

INTRODUCTION: Gliomatosis cerebri (GC) is a highly infiltrative glial neoplastic lesion that involves at least three lobes (as defined by WHO 2007). GC can appear as primary GC or result from a spread of a focal glioma and it is usually an aggressive neoplasm corresponding to WHO grade III. Due to the tumor extension, patients are generally not candidate to surgical resection, but biopsy is performed in order to obtain an histological diagnosis. Prognosis remains limited despite treatment with chemotherapy and/or radiotherapy. MATERIALS AND METHODS: We retrospectively analysed patients with GC who underwent surgery at our Institution from 2001 to 2012. We focused on the type (biopsy vs partial resection) and the outcome of surgery at the time of diagnosis and the role of surgery at tumor progression. Diagnosis of GC in patients whose histological evaluation after surgery resulted not conclusive was defined by MR spectroscopy (MRS) and/or by IDH1 mutation immunohistochemistry. RESULTS: We collected a total of 38 patients with diagnosis of GC treated at our Institution. 24 out of 38 (63%) were males. Median age at diagnosis was 50.5 (range: 21-72), median KPS at diagnosis was 80 (range: 60-100). As for the MRI patterns at the time of diagnosis, contrast enhancement (CE) was absent in 21/38 (55%) and mild-patchy in 17/38 (45%). 25 patients out of 38 (66%) underwent biopsy only, 13/38 (34%) underwent partial resection. In the group of patients who underwent biopsy the median age at diagnosis was 52 (range: 21-72), median KPS at diagnosis was 80 (range: 60-90).Two patients had serious hemorrhage after biopsy. Histological diagnosis was conclusive in 22/25 (88%), while in three patients histological diagnosis was aspecific gliosis. Median overall survival (OS) in this group of patients was: 17 months (range: 7 months-10 years). 7 patients out of 25 (28%) are still alive. In the group of patients who underwent partial resection the median age at diagnosis was 50 (range: 25-66), median KPS at diagnosis was 80 (range: 70-100) and was unchanged after surgery. Histological diagnosis was conclusive in all patients (100%). Median OS was: 22 months (range: 4.5 months-9 years). Three patients out of 12 (25%) are still alive. Four patients underwent surgical resection of a symptomatic enhancing lesion at the time of tumor progression after treatments (chemotherapy and/or radiotherapy). In 2 patients KPS improved after surgery, while in the remaining patients KPS was stable. Median OS after second surgery was 6 months. One patient is still alive. CONCLUSIONS: Compared to biopsy alone, partial resection that provides more tissue to the neuropathologist, allows an increase of “conclusive” histological diagnosis. Type of surgery at diagnosis could impact the outcome. Second surgery can be an option at the time of tumor progression when patient develops a focal, enhancing, symptomatic mass.