biostudies-literatureDashti NKNCI NIH HHSe70015https://www.ebi.ac.uk/biostudies/studies/S-EPMC11977784biostudies-literatureUnknown63(11)Conventional high-grade osteosarcomas are characterized by aggressive radiologic features, cytologic pleomorphism, and complex genomics. However, rare examples of osteosarcomas remain challenging due to unusual histology, such as sclerosing or osteoblastoma-like features, which may require molecular confirmation of their complex genetic alterations. We have encountered such a case in a 17-year-old man, who presented with a third metatarsal sclerotic bone lesion, found incidentally in the work-up of a foot trauma. The initial imaging revealed a lesion with sclerotic/blastic features proximally and lucent/lytic portion distally, findings interpreted consistent with osteoblastoma. The lesion was managed intra-lesionally with curettings and cryoablation; however, the microscopic findings were Genes, chromosomes & cancerMalignant Bone-Forming Neoplasm With NIPBL::BEND2 Fusion.PMC11977784P30 CA008748P50 CA217694Dashti NKMatcuk GAgaimy AAntonescu CRSaoud CfalseMalignant Bone-Forming Neoplasm With NIPBL::BEND2 Fusion.Conventional high-grade osteosarcomas are characterized by aggressive radiologic features, cytologic pleomorphism, and complex genomics. However, rare examples of osteosarcomas remain challenging due to unusual histology, such as sclerosing or osteoblastoma-like features, which may require molecular confirmation of their complex genetic alterations. We have encountered such a case in a 17-year-old man, who presented with a third metatarsal sclerotic bone lesion, found incidentally in the work-up of a foot trauma. The initial imaging revealed a lesion with sclerotic/blastic features proximally and lucent/lytic portion distally, findings interpreted consistent with osteoblastoma. The lesion was managed intra-lesionally with curettings and cryoablation; however, the microscopic findings were 2024-01-01T00:00:00Z2024 Nov2026-05-15T03:17:23.801Z2026-05-15T03:12:17.337ZS-EPMC119777843960414310.1002/gcc.70015