Introduction: Primary pancreatic B-cell lymphoma (PPL) is rather rare and accounts for less than 1% of all pancreatic lesions with Non Hodgkins lymphoma NHL) being the commonesrt histological variant. Identification of PPL is important since they respond better tp treatment and hence carry better prognosis than adenocarcinoma. Case presentation: A 66-year-old man presented with one-month history of progressively worsening jaundice, dark urine and itching. CT scan of the abdomen revealed 7.2x6.6x6.2 cm mass arising from the head of pancreas (HOP), with decreased enhancement relative to the pancreas, and encasing the proximal SMA, celiac artery and portal vein. Also was noted a prominence of CBD likely due to compression and encasement by the mass. Laboratory workup was significant for total bilirubin 22.6 mg/dL, AST 105 IU/L, ALT 79 IU/L, ALP 330 IU/L, with normal CA 19.9 (32 U/ml) and CEA (1.6 ng/ml). He was referred to us for presumed pancreatic adenocarcinoma. EUS did not show any obvious well-circumscribed HOP mass but dilated pancreatic duct (6 mm) and CBD, with a large conglomerate of peripancreatic lymph nodes, which were biopsied. ERCP revealed 4 cm distal CBD stricture, brushings of which had negative cytology. The lymph node FNA disclosed this to be diffuse large B cell lymphoma. Patient was then referred to oncology and initiated on R-CHOP regimen with good response. Discussion: PPL is a rare tumor of pancreas, which often mimics pancreatic adenocarcinoma. PPL usually has non-specific presenting symptoms, but can occasionally manifest as obstructive jaundice or small bowel obstruction. Differentiation of PPL from secondary involvement of pancreas by NHL may be suggested by 1) its location confined within the pancreas, with frequent peri-pancreatic lymphadenopathy, 2) no palpable superficial lymphadenopathy, 3) no hepatosplenic involvement or mediastinal nodal enlargement on chest imaging and 4) normal white blood cell count. Imaging alone is insufficient for adequate differentiation of PPL from adenocarcinoma, and hence tissue acquisition by EUS is quintessential and highly accurate. Treatment of PPL requires a combination of chemo-radiation, rather than surgery, which by itself does not improve survival in PPL patients. Practicing gastroenterologists must remain cognizant of this rare but important differential of pancreatic adenocarcinoma, in order to provide timely and accurate management advise to their patients.Figure 1