title: A case of osteoclast-like giant cell-rich epithelioid glioblastoma with BRAF V600E mutation.
abstract: Epithelioid glioblastomas (E-GBMs) are rare, highly aggressive tumors consisting of closely packed tumor cells with smooth, round cell borders and abundant eosinophilic cytoplasm. They tend to affect younger patients compared with conventional GBM. BRAF V600E mutation is characteristically found in approximately 50% of all E-GBMs, compared with a low frequency of this mutation in conventional GBM. Here, we report an unusual case of glioma involving the right frontal lobe, basal ganglia and thalamus in an HIV-positive 30-year-old man on antiretroviral therapy. The lesion was composed of abundant discohesive, monotonous epithelioid cells with extensive necrosis, spindle and polyhedral cells, low-grade oligoastrocytoma-like areas, sarcomatous components, and numerous osteoclast-like giant cells (OLGCs) intermingled with epithelioid tumor cells. As the epithelioid cells accounted for more than one-third of the tumor, a pathological diagnosis of E-GBM was made. BRAF V600E mutation was detected in both oligoastrocytoma-like and epithelioid cell components. Similar to previously reported findings on E-GBM associated with low-grade glioma, this case suggested that low-grade astrocytic glioma with BRAF V600E mutation progressed to E-GBM. OLGCs are rarely observed in gliomas, and this is the first case report of E-GBM associated with abundant OLGC infiltration.
authors.affiliation: Department of Pathology, Cancer and Infectious Disease Center Tokyo Metropolitan Komagome Hospital, 3-18-22 Honkomagome, Bunkyo-ku, Tokyo, 113-8677, Japan. funata@cick.jp.
authors.forename: Nobuaki
authors.initials: N
authors.lastname: Funata
authors.affiliation: Department of Human Pathology, Gunma University Graduate School of Medicine, 3-39-22 Showa-machi, Maebashi, Gunma, Japan.
authors.forename: Sumihito
authors.initials: S
authors.lastname: Nobusawa
authors.affiliation: Department of Neurosurgery, Cancer and Infectious Disease Center Tokyo Metropolitan Komagome Hospital, 3-18-22 Honkomagome, Bunkyo-ku, Tokyo, Japan.
authors.forename: Ryoji
authors.initials: R
authors.lastname: Yamada
authors.affiliation: Department of Neurosurgery, Cancer and Infectious Disease Center Tokyo Metropolitan Komagome Hospital, 3-18-22 Honkomagome, Bunkyo-ku, Tokyo, Japan.
authors.forename: Nobusada
authors.initials: N
authors.lastname: Shinoura
mesh_terms: D000328:Adult; D001254:Astrocytoma / Q000175:diagnosis / Q000235:genetics / Q000473:pathology; D001479:Basal Ganglia / Q000473:pathology; D001932:Brain Neoplasms / Q000175:diagnosis / Q000235:genetics* / Q000473:pathology*; D002471:Cell Transformation, Neoplastic; D018450:Disease Progression; D005625:Frontal Lobe / Q000473:pathology; D015726:Giant Cells / Q000473:pathology; D005909:Glioblastoma / Q000175:diagnosis / Q000235:genetics* / Q000473:pathology*; D006679:HIV Seropositivity; D006801:Humans; D008297:Male; D009154:Mutation; D010010:Osteoclasts / Q000473:pathology; D048493:Proto-Oncogene Proteins B-raf / Q000235:genetics*; D013788:Thalamus / Q000473:pathology
chemical_list: C482119:BRAF protein, human; D048493:Proto-Oncogene Proteins B-raf
keywords: BRAF V600E mutation; Epithelioid glioblastoma; Gliosarcoma; Osteoclast-like giant cells