S1380 A Rare Case of Pancreatic Plasma Cell Myeloma Presenting as Obstructive Jaundice: A Case Report and Review of Literature

Abstract

INTRODUCTION: Hematological malignancies affect the pancreas very rarely, with lymphomas being the most common. Pancreatic plasma cell myeloma (PCM) is exceptionally uncommon. We present a case of obstructive jaundice in a patient due to pancreatic PCM. CASE DESCRIPTION/METHODS: A 50-year old man with a history of hypertension, hyperlipidemia, and nephrolithiasis presented to the emergency department with a 3-month history of worsening mid-epigastric pain, weight loss, and jaundice. Initial laboratory workup showed low hemoglobin (11.0 g/dL), hyperbilirubinemia, and elevated protein gap. C-reactive protein and erythrocyte sedimentation rate were elevated, while vitamin B-12 and folate levels were found normal. Computed tomography revealed intra and extrahepatic biliary ductal dilatation and a hyperenhancing mass within the pancreas and porta hepatis with portal vein compression (Figure 1). Multiple enlarged retroperitoneal lymph nodes, splenomegaly, and lytic lesions in the right pubic bone were also noted. Prostate-specific antigen (PSA) and carcinoembryonic antigen (CEA) levels were normal, while CA-19-9 was found to be 191 (Normal: 0-37 U/mL). Endoscopic retrograde cholangiopancreatography (ERCP) and stenting were performed for a malignant appearing common bile duct stricture (Figure 2). Urine protein electrophoresis (UPEP) revealed a monoclonal M spike (4.7 g/dL) and gamma globulins with lambda light chains in the urine. Immunofixation confirmed the monoclonality and demonstrated IgG lambda protein. Quantitative testing showed a high level of IgG at 6.5 g/dL (Reference range: 0.7-1.6 g/dL) with decreased IgA and IgM. Biopsy of pancreatic mass and bone lesions revealed plasmacytoma with lambda light chain restriction. Bortezomib and dexamethasone were initiated with the resolution of the biliary obstruction (Figure 3). The presence of extramedullary plasmacytoma (EMP), lytic bone lesions, anemia, and monoclonal immunoglobulin production was suggestive of multiple myeloma. DISCUSSION: Pancreatic PCM typically presents with obstructive jaundice, but pancreatitis, gastrointestinal bleeding, and nausea can also occur. Pancreatic PCM offers a diagnostic challenge and should not be overlooked when evaluating hyperbilirubinemia due to obstructive jaundice if retroperitoneal lymphadenopathy and osteolytic lesions are present.Figure 1.: Arrow pointing towards pancreatic mass.Figure 2.: Arrow pointing towards common bile duct stricture.Figure 3.: Arrow pointing towards resolution of common bile duct stricture.