Astroblastoma: A molecularly defined entity, its clinico-radiological & pathological analysis of eight cases and review of literature

Abstract

Astroblastoma, a unique entity of glial tumor, predominantly occur in young women with distinctive MN1 rearrangement, Given its limited documentation in existing literature, we report eight cases of astroblastoma, detailing their clinical, radiological, and histopathological characteristics along with molecular analysis. We conducted a retrospective analysis of our neuropathology archive database spanning the past 8 years. We included all cases that underwent Magnetic Resonance Imaging (MRI), surgical resection, histopathological examination, molecular testing, and follow-up. Histopathological examination involving immunohistochemistry and Fluorescence In Situ Hybridization (FISH) was carried out for all cases. All tumors were found to be located in the supratentorial region (cerebral hemisphere). The median age of the group was 35.1 years, with a female-to-male ratio of 1.6:1. The most common clinical presentation was headache. Morphologically, all tumors exhibited astroblastic features with pseudorosettes and perivascular hyalinization. Immunohistochemistry consistently revealed positivity for EMA and variable immunoreactivity for GFAP, OLIG2, and D2–40. Fluorescence In Situ Hybridization (FISH) analysis conducted for all cases showed MN1 rearrangement in 7 cases. The mean follow-up period was 45 months (ranging from 12 to 105 months). Radiotherapy was administered for high-grade and recurrent astroblastomas. All patients are currently alive and in good health. Astroblastomas are uncommon central nervous system (CNS) tumors with characteristics morphology and molecular signatures. They typically carry a favorable prognosis. High level suspicion is required for their diagnosis and molecular analysis is must to distinguish them from other morphological mimics.