Multiple Myeloma and Change of ABO Blood Group Type: A Case Report

Multiple myeloma is a hematopoietic stem cell malignancy that involves the plasma cells. It starts insidiously and usually involves males in their 60's. Clinical manifestations usually include anemia, kidney disease, hypercalcemia, and bone pains. We present a male with multiple myeloma whose blood group changed from AB positive to O positive. ABO blood group change can occur in multiple myeloma so blood group should be checked thoroughly in patients with hematological malignancies to prevent serious hematological reactions.