Gastrointestinal plasmacytoma that caused anemia in a patient with multiple myeloma

Background: A 70-year-old white male diagnosed with IgA lambda multiple myeloma, who had been treated with two cycles of melphalan and prednisone, was evaluated for persistent anemia. He had required more than 15 U of packed red blood cells within a 2-month period for his anemia, despite recombinant erythropoietin treatment, and his hemoglobin level was persistently below 9 g/dl. Investigations: Physical examination and laboratory tests, which included a red blood cell mean corpuscular volume, platelet counts, coagulation studies, a peripheral blood smear, lactate dehydrogenase level, haptoglobin and bilirubin level, vitamin B₁₂ and folate level, serum iron studies, bone marrow biopsy and immunophenotyping. Additionally, Congo red staining of the subcutaneous fat aspirate and a bone marrow biopsy were carried out, as well as esophagogastroduodenoscopy with gastric and duodenal biopsies. Diagnosis: Gastrointestinal plasmacytoma. Management: Control of underlying disease (multiple myeloma) with 2 cycles of treatment with melphalan and prednisone followed by high-dose pulse dexamethasone chemotherapy as outlined by the oncologist. PPI therapy was continued and NSAIDs were avoided. The patient died because of infectious complications with subsequent multi-organ failure while awaiting work up for autologous stem cell transplantation.