Sunray appearance

A radiologic pattern of aggressive, spiculated periosteal reaction in which linear ossified spicules radiate perpendicularly or obliquely from the cortex, resembling rays of the sun. It is classically associated with malignant bone tumors such as osteosarcoma, Ewing sarcoma, bone metastasis, intraosseous hemangioma, plasmacytoma/multiple myeloma, tuberculosis, and osteomyelitis.