Overview of included O-DLBCL and NO-DLBCL cohorts and subentities with specific anatomical localizations. (A) Flowchart of included and analyzed O-DLBCL and NO-DLBCL subentities. A total of 103 DLBCL cases with osseous involvement were subdivided into three O-DLBCL stages, with PB-DLBCL (n = 41), polyostotic-DLBCL (n = 14), and disseminated-DLBCL (n = 48). Of these, 20 cases failed tNGS quality controls (insufficient DNA or high number of deamination variants), and 83 cases attained appropriate sequencing results. In addition, 63 NO-DLBCL-GCB cases were included as a comparator. Furthermore, 63 samples with adequate RNA were sent for NanoString analysis, of which 3 failed analysis. In total, 24 PB-DLBCL, 5 polyostotic-DLBCL, 11 disseminated-DLBCL, and 20 NO-DLBCL-GCB cases were successfully analyzed with the NanoString platform. (B) Radiologic imaging of International Extranodal Lymphoma Study Group staging system with 3 anatomically defined stages: PB-DLBCL, with a single bone lesion with or without regional involvement of lymph nodes; polyostotic lymphoma (polyostotic-DLBCL), with multifocal disease in a single bone or multiple affected bones; and disseminated lymphoma (disseminated-DLBCL) with ≥1 bone lesion(s) and ≥1 (extra)nodal localization(s).²  NO-GCB-DLBCL was defined as nodal, mixed (nodal and extranodal involvement), or only extranodal localization(s), without any osseous involvement. (C) Frequencies of anatomical osseous localizations identified in all 103 O-DLBCL subentities. Other osseous localizations consisted of one calcaneus, cuneiform, metacarpal III, or talus. (D) Frequencies of anatomical nonosseous localizations of 63 NO-DLBCL-GCBs. CNS, central nervous system.