Diffusely infiltrating glioma with CREBBP–BCORL1 fusion showing overexpression of not only BCORL1 but BCOR: A case report

• Published in: Brain tumor pathology Vol. 39; no. 3; pp. 171 - 178
• Main Authors: Yamazaki, Ayako, Arai, Yasuhito, Fukuoka, Kohei, Nakano, Yoshiko, Hama, Natsuko, Nakata, Satoshi, Makino, Keishi, Kuroda, Jun-Ichiro, Shinojima, Naoki, Mukasa, Akitake, Mikami, Yoshiki, Ichimura, Koichi, Shibata, Tatsuhiro, Yokoo, Hideaki, Nobusawa, Sumihito
• Format: Journal Article
• Language: English
• Published: Singapore Springer Nature Singapore 01.07.2022; Springer Nature B.V
• Subjects: Brain cancer; Cancer Research; Case Report; Chemotherapy; DNA methylation; Glioma; Kinases; Magnetic resonance imaging; Medicine; Medicine & Public Health; Neurology; Neurosurgery; Oncology; Pathology; Proteins; RNA polymerase; Sarcoma; Surgery; Tomography; Tumors; EP300; CREBBP; BCOR; Glioma; BCORL1
• ISSN: 1433-7398; 1861-387X
• DOI: 10.1007/s10014-022-00435-4

BCORL1 encodes a transcriptional corepressor homolog to BCOR. BCORL1 rearrangements have been previously described as rare events, and among them, CREBBP–BCORL1 has been reported only in 2 cases of ossifying fibromyxoid tumors. Herein, we present the first case of diffusely infiltrating glioma with CREBBP–BCORL1 involving a 17-year-old female patient. Histologically, the tumor was composed of a diffusely infiltrative proliferation of small tumor cells with moderate cellularity showing prominent microcystic formation. DNA methylation analysis revealed that the current case and a previously reported anaplastic ependymoma with EP300 – BCORL1 were clustered together in close proximity to but distinct from methylation class high-grade neuroepithelial tumor with BCOR alteration. RNA sequencing demonstrated high mRNA expression of not only BCORL1 but BCOR , and the latter was compatible with diffuse nuclear expression of BCOR detected by immunohistochemistry. Our findings suggest that central nervous system tumors with CREBBP / EP300 - BCORL1 may exhibit diverse morphologies but form a distinct DNA methylation group and that BCORL1 fusion genes may lead to upregulation of both BCOR and BCORL1 .