EPCO-38. PRIMARY CNS DIFFUSE LARGE B-CELL LYMPHOMA WITH CIC-REARRANGEMENT IDENTIFYING FROM PAN-CANCER PATIENTS EXCLUDING SARCOMAS

Abstract

Abstract BACKGROUND CIC-rearrangements most commonly occur in patients with Ewing-like sarcomas, an emerging class of round cell sarcomas. CIC sarcoma has considered being a new entity in CNS tumors by cIMPACT-NOW conform classification of tumors of soft tissue and bone. However, not all patients harbor CIC fusion are sarcoma cases. Herein, we firstly report a case of primary CNS diffuse large B-cell lymphoma (DLBCL) harboring CIC-rearrangement with a novel partner. METHODS CIC fusions were screened in the tumor tissue or peripheral blood from 3,961 cases with different types of cancer excluded patients with sarcomas. Comprehensive genomic profiling with a 539 cancer-related genes panel was administrated based on next generation sequencing (NGS) which is adept in finding novel fusion mutations. The pathology diagnosis of every case was confirmed via hematoxylin and eosin (H&E) stained. RESULTS Among the whole 3,961 cases, 3 CIC-rearrangements were observed. One case has been reported yet, one was a patient with lung adenocarcinoma, the last one was a patient harboring POU2F2 (Exon5) -CIC (Exon 11) with CNS arisen tumor, primary DLBCL. Literature review revealed only CIC-LEUTX was reported not only in sarcomas, but also in anaplastic ganglioglioma and CNS embryonal tumors. The partners of CIC sarcomas included DUX4, NUTM1, NUTM2A, FOXO4 and LEUTX, and whether specific partner affected biology of CIC-rearrangement tumors. CONCLUSIONS CIC-rearrangement arises in another type of brain cancer besides glioma and embryonal tumor, primary CNS DLBCL. Observation of novel partner provides new basis for further study of biology function of them in CIC fusions. Our study also indicates the presence of a specific tumor type with distinct histopathology driven by CIC fusions can be classified via CIC molecular pathology.