Duodenal involvement in multiple myeloma

Abstract

A 48-year-old man presented with a 1-week history of epigastric pain and dyspepsia. Multiple myeloma with monoclonal gammopathy was diagnosed 1 year previously, and he was treated with chemotherapy and autologous bone marrow transplantation. Until recently, he had received high dose oral dexamethasone and his disease was in remission according to all clinical and laboratory data. Esophago-gastro-duodenoscopy showed a huge ulcerative mass in the second portion of the duodenum (Fig. 1A). A biopsy was performed: on light microscopy, there was diffuse infiltration of atypical plasma cells in the duodenal mucosa that mimicked malignant lymphoma histologically (Fig. 2A, H & E, ×400). On immunohistochemical staining, the neoplastic plasma cells were diffusely positive for CD138 (Fig. 2B) and negative for CD20 and CD3. Abdominal computer tomography demonstrated a huge mass in the second duodenal portion (Fig. 1B; arrow) and multiple lymphadenopathies in the periduodenal, portocarval, peripancreatic, and aortocaval areas. Duodenal involvement of multiple myeloma with lymphadenopathy as diagnosed, and radiotherapy and chemotherapy were initiated.