Concurrent Multiple Myeloma and Metastatic Osteosarcoma: A Case Report and Literature Review.

Multiple myeloma (MM) and osteosarcoma (OS) are two common bone malignancies, however, the simultaneous occurrence of both primary bone tumors in the same patient has not been reported in the United States to date. We present a unique case in which both malignancies present concurrently in a 72-year-old man. Results of spinal magnetic resonance imaging (MRI), radiographic skeletal survey, and hematological workup established the initial diagnosis of MM.