Primary Pancreatic Lymphoma Evaluated by Fine-Needle Aspiration clinical, radiologic, and Pathological correlation

Objectives: Primary pancreatic lymphoma (PPL) is rare, mimicking pancreatic ductal adenocarcinoma (PDAC) clinically and radiologically. The aim of this study is to evaluate the clinical, radiologic, and pathological characteristics of PPL diagnosed by fine-needle aspiration (FNA) in our institution. Methods: Patient clinical, radiologic, and pathological information was collected from the electronic health record system. Results: In total, 11 of 4,353 pancreatic FNAs met the criteria. The most common clinical symptom was jaundice, followed by abdominal pain, weight loss, and diarrhea. Abnormal laboratory findings included elevated alkaline phosphatase, total bilirubin, lactate dehydrogenase, and cancer antigen 19-9. Abnormal radiologic findings included pancreatic mass, biliary dilatation, vessel encasement, and common bile duct encasement and thickening. Five patients underwent more than 1 tissue sampling procedure before the final diagnosis of lymphoma. Final pathologic diagnosis included 7 large B-cell lymphomas and 4 follicular lymphomas. Flow cytometric analysis was performed on 9 specimens, and all demonstrated an aberrant monoclonal B-cell population. Conclusions: PPL mimics PDAC clinically and radiologically and could be a challenge for pathologic diagnosis if lymphoma is not included in the differential diagnosis during immediate evaluation. If lymphoma is suspected during immediate evaluation, PPL could be reliably diagnosed by FNA with the aid of ancillary studies.