1415 A Rare Presentation of Diffuse Large B-Cell Lymphoma as a Pancreatic Mass

Abstract

INTRODUCTION: Diffuse Large B-Cell Lymphoma (DLBCL) of Pancreas is a fast-growing Non-Hodgkin lymphoma (NHL), which accounts for only 0.5% of all pancreatic tumors. In most cases, it presents as a single, metastatic mass or diffuse nodules in the pancreas. DLBCL should be considered in patients with a pancreatic mass, especially if: personal history of lymphoma, presence of an immunodeficiency syndrome, or prior infection with EBV. CASE DESCRIPTION/METHODS: A 60-year-old type II diabetic male presented to the ED with nausea, vomiting, diarrhea and 40 lb weight loss. Patient's mother had known pancreatic adenocarcinoma. Social history revealed multiple sexual partners of both sexes. On exam patient had epigastric tenderness, and a 1 cm non-tender supraclavicular lymph node. A CT abdomen/pelvis with contrast revealed a 4.8 × 7.5 × 4 cm mass in the head of the pancreas and retroperitoneal metastatic adenopathy. Endoscopic ultrasound characterized a “U” shaped parenchymal mass extending from the head to the tail of the pancreas encircling the splenic artery. Fine needle aspiration and biopsy both revealed DLBCL. Bone marrow biopsy and imaging studies were unremarkable, therefore the pancreas was determined to be the primary site. Additional testing found the patient to be HIV positive with a CD4 count of 119 and thus diagnosed with AIDS. He was started on antiretroviral therapy prior to initiation of R-CHOP (Rituximab, Cyclophosphamide, Doxorubicin, Vincristine and Prednisone). Following his first chemotherapy dose, he was readmitted to the hospital with fever and weakness. Patient continued to decompensate and expired 23 days from his initial diagnosis. DISCUSSION: Most common sites of extranodal involvement of NHL are the gastrointestinal tract, liver, lung, bone marrow, and the central nervous system. DLBCL can present with extra-nodal involvement in about 50% of cases, but only 0.2-2% involve the pancreas. Clinically, most cases of Primary Pancreatic Lymphoma (PPL) are misdiagnosed as pancreatic adenocarcinoma. PPL generally carries a better prognosis once treatment is initiated in an immunocompetent individual. In this rare case, the patient was concurrently diagnosed with AIDS and Stage IV DLBCL of the pancreas. This case highlights an unusual presentation of a primary pancreatic malignancy that typically presents as a metastatic lesion. Furthermore, this case shows the utility of endoscopic ultrasound to better identify and characterize pancreatic masses when compared to other diagnostic modalities.