S3449 Deceptive Mass: The Hidden Threat of Necrotic Pancreatic Lymphoma

Introduction: Diffuse large B-cell lymphoma (DLBCL) is the most common subtype of non-Hodgkin’s lymphoma, presenting as a rapidly growing mass in older adults. It can occur in nodal or extranodal regions, with primary pancreatic lymphoma being a rare but important differential diagnosis for pancreatic head masses. Symptoms are often non-specific and include abdominal pain, weight loss, and jaundice. Distinguishing pancreatic lymphoma from adenocarcinoma is crucial, as treatment and prognosis differ significantly. Notably, necrosis in DLBCL can worsen prognosis and reduce treatment response. Case Description/Methods: A 74-year-old woman with hypertension, hypothyroidism, and Crohn’s disease presented for an endoscopic ultrasound (EUS) after a low-dose computed tomography scan revealed a 6 cm pancreatic head mass. Fine-needle aspiration (FNA) was performed but complicated by post-procedure bleeding and clot formation. The patient denied a personal history of pancreatic disorders but reported parental cancer. Laboratory findings revealed anemia (Hb 9.2 g/dL) and elevated liver function tests (total bilirubin 2.6 mg/dL, AST 146 U/L, ALP 267 U/L, ALT 158 U/L). Magnetic resonance cholangiopancreatography (MRCP) showed a centrally necrotic pancreatic mass without ductal dilation. A PET scan demonstrated hypermetabolic lymph nodes in the left upper neck and abdomen. Histopathology of the mass confirmed necrotic DLBCL. The patient was started on Protonix, scheduled for follow-up imaging, and referred for outpatient hepatobiliary surgery consultation. Discussion: Primary pancreatic lymphoma, though rare, should be considered in the differential for pancreatic masses. It typically involves peripancreatic nodes, lacks mediastinal lymphadenopathy, and does not cause main duct dilation. Unlike adenocarcinoma, lymphoma rarely invades vascular structures, making imaging and biopsy crucial for diagnosis. DLBCL is aggressive and biologically diverse. Management depends on subtype, with germinal center variants responding well to R-CHOP (rituximab, cyclophosphamide, prednisone, doxorubicin, vincristine), while activated B-cell subtypes have worse outcomes. Prognosis is influenced by disease stage, extranodal spread, and lactate dehydrogenase levels. Considering lymphoma in pancreatic masses ensures early diagnosis. A thorough workup with imaging and biopsy allows for proper treatment, avoids unnecessary surgery, and improves patient outcomes.