MM-010 Spontaneous Prosthetic Fracture in a Patient With Relapsed Multiple Myeloma

Abstract

Plasmacytomas are a form of plasma cell dyscrasia that present as a single mass of monoclonal plasma cells located either extramedullary or intraosseous. They can present as a solitary or multiple mass, either at diagnostic or in the context of a relapsed refractory patient. The latter scenario usually has a dismal prognosis. Bone fractures are frequent in patients with multiple myeloma (MM), sometimes requiring a surgical approach. Eventually, plasmacytomas can also develop surrounding a synthetic prothesis. Prosthetic fractures are a rare complication and usually present a challenging situation. To describe a case of prosthetic spontaneous fracture and exposure. Case report. A 52-year-old woman with a history of IgG kappa MM diagnosed in 2014 was admitted for severe back pain. Her MM was treated with CyBorD and consolidation with an autologous stem cell transplant. She also underwent surgery for a dorsal vertebral fracture at diagnosis. She had a first relapse in 2018 receiving a carfilzomib-based regimen as re-induction. In 2019 she had a 3° relapse with extensive bone disease and supraclavicular plasmacytoma in a lymph node. She received VTD-PACE for 3 cycles, achieving a partial response. At admission in 2020, dorsal x-ray showed prosthetic fracture. She also had a dorsal plasmacytoma. Her ECOG performance status was 4, and she received palliative care and a VAD regimen. The plasmacytoma continued to grow and ulcerated. Prothesis exposure was confirmed. Because of her bad performance status, she received palliative treatment. Extramedullary relapses of plasma cell dyscrasias are usually aggressive and have a dismal prognosis. Rare reports and recommendations are available in the literature regarding the treatment of prosthetic fractures, and there is currently no consensus about the standard management for these patients. We present this case because of the rare incidence of prosthetic fractures.