Histologic Definition of Enhancing Core and FLAIR Hyperintensity Region of Glioblastoma, IDH-Wild Type: A Clinico-Pathologic Study on a Single-Institution Series

• Published in: Brain sciences 2023-01, Vol.13 (2), p.248
• Main Authors: Broggi, Giuseppe, Altieri, Roberto, Barresi, Valeria, Certo, Francesco, Barbagallo, Giuseppe Maria Vincenzo, Zanelli, Magda, Palicelli, Andrea, Magro, Gaetano, Caltabiano, Rosario
• Format: Article
• Language: English
• Subjects: Aminolevulinic acid; Biopsy; Brain cancer; Brief Report; Diseases; enhancing core; FLAIR; Fluorescence; Glioblastoma; Glioblastoma multiforme; Gliosis; histopathology; Magnetic resonance imaging; Medical prognosis; Medical research; Medicine, Experimental; Morphology; Neuropathology; Oncology; Relapse; Substantia alba; Substantia grisea; Tumor cells; Tumors
• ISSN: 2076-3425; 2076-3425
• DOI: 10.3390/brainsci13020248

The extent of resection beyond the enhancing core (EC) in glioblastoma IDH-wild type (GBM, IDHwt) is one of the most debated topics in neuro-oncology. Indeed, it has been demonstrated that local disease recurrence often arises in peritumoral areas and that radiologically-defined FLAIR hyperintensity areas of GBM IDHwt are often visible beyond the conventional EC. Therefore, the need to extend the surgical resection also to the FLAIR hyperintensity areas is a matter of debate. Since little is known about the histological composition of FLAIR hyperintensity regions, in this study we aimed to provide a comprehensive description of the histological features of EC and FLAIR hyperintensity regions sampled intraoperatively using neuronavigation and 5-aminolevulinic acid (5-ALA) fluorescence, in 33 patients with GBM, IDHwt. Assessing a total 109 histological samples, we found that FLAIR areas consisted in: (i) fragments of white matter focally to diffusely infiltrated by tumor cells in 76% of cases; (ii) a mixture of white matter with reactive astrogliosis and grey matter with perineuronal satellitosis in 15% and (iii) tumor tissue in 9%. A deeper knowledge of the histology of FLAIR hyperintensity areas in GBM, IDH-wt may serve to better guide neurosurgeons on the choice of the most appropriate surgical approach in patients with this neoplasm.