A diffusely enlarged pancreas: the (un)usual suspect.

An 81-years-old female presented with obstructive jaundice and a non-specific clinical picture of nausea and appetite loss. Labs demonstrated a conjugated hyperbilirrubinemia (7.7 mg/dL), increased aspartate aminotransferase and alanine aminotransferase (10xULN and 8xULN, respectively), increased lactate dehydrogenase (10xULN) and serum lipase (3xULN). CA 19.9 was 342 U/mL (Ref value < 37 U/mL). There was no evidence of peripheral lymphadenopathy or hepatosplenomegaly. Imaging (Figure 1A and 1B) revealed a marked homogeneous enlargement of the pancreas (without any well-defined mass), dilation of the extra and intra-hepatic bile ducts and ascites. Endoscopic ultrasound (Figure 1C and 1D) identified an enlarged homogeneous hypoechoic pancreas, without any well-defined lesion, no dilation of the main pancreatic duct, no peripancreatic or celiac enlarged lymph nodes. A fine-needle biopsy was performed yielding, on cytological examination and cell-block technique (Figure 2A and 2B), numerous medium/large sized atypical lymphoid cells that displayed a B-cell lineage immunophenotype (Figure 2A-2F). Even though, further characterization (by flow cytometric immunophenotyping) could not be obtained, a final diagnosis of primary pancreatic lymphoma (PPL) was assumed. Primary pancreatic lymphoma is a remarkably rare tumor of the pancreas, representing approximately 0.5% of all pancreatic neoplasms and <2% of all lymphomas (1,2). A correct diagnosis is crucial because therapeutic management differs from other pancreatic malignancies (pancreatic ductal adenocarcinoma, neuroendocrine tumor and metastases) (2,3). Two morphologic patterns of PPL are recognized: a focal form (occurring in the pancreatic head in 80% of cases) and a rarer diffuse/infiltrative pattern, as depicted herein, emulating an acute/autoimmune pancreatitis (1).