A rare case of CD38-negative abdominal multiple extramedullary plasmacytoma and literature review.

Abdominal multiple extramedullary plasmacytoma (EMP) is a rare disease. CD38-negative relapsed/refractory EMP after treatment with daratumumab has never been reported. In 2020, a patient with jaundice was diagnosed with plasmacytoma in another hospital, which progressed one year after receiving multiline therapy. In July 2021, he was admitted to our hospital and showed CD38-pogative plasmacytoma. The patient received 2 cycles of treatment including daratumumab, venetoclax and DCEP chemotherapy and achieved partial remission. However, he developed ascites and eventually died. Our case indicated that multiple EMP has much lower incidence and far worse prognosis than solitary EMP.