Simultaneous medication-related osteonecrosis of the jaw and maxillo-mandibular localization of multiple myeloma

Bone resorption inhibitors, such as bisphosphonates (BPs) and denosumab (DB), are widely used for the treatment of bone disease in patients with multiple myeloma (MM) and metastatic cancer. These antiresorptive therapies however increase the risk of developing medication-related osteonecrosis of the jaw (MRONJ), whose diagnosis is based on both clinical signs, such as exposed necrotic bone, purulent drainage and pathologic fracture, and radiographic findings, such as structural alteration of the bone, erosion and sequestrum. While localization of MM at the jaw is a rare sign of presentation, it is quite commonly found in the advanced disease. Of note, the simultaneous finding of MM and MRONJ at the same site has been rarely reported. Here, we present a case of advanced MM in an 82-year-old man with a history of BP administration presenting with MRONJ characterized by mandibular pathological fracture and maxillary bone exposure, positive for myeloma plasma cells on histopathological examination.