The enigma of multicentric glioblastoma: physiopathogenic hypothesis and discussion about two cases.

Two men were admitted following generalized seizures. Cerebral MRI-scans showed multiple independent enhancing lesions which were bilateral (first case) and unilateral but disseminated to the brainstem (second case). Whole-body CT-scans showed no primaries. Both cases were diagnosed by biopsy as IDH1 wild-type multicentric glioblastoma. Treatment of both was palliative. The natural history of this entity remains matter of debate but 2 genomic analysis strikingly revealed that foci from the same patient were of monoclonal origin. Consistently, these 2 cases could sustain the hypothesis that an anatomical connectivity exists between the different foci of a multicentric glioblastoma.