Primary pancreatic lymphoma evaluated by fine-needle aspiration: findings in 14 cases

Fine-needle aspiration (FNA) is a popular method for evaluating pancreatic lesions. There is considerable literature on FNA evaluation of primary pancreatic carcinomas, but few studies address the FNA diagnosis of primary pancreatic lymphoma. We reviewed 14 cases of atypical lymphoid processes diagnosed by FNA during a 5-year period, constituting 1.3% of a total of 1,050 pancreatic FNA cases. The diagnoses were as follows: 6 large B-cell lymphomas, 4 follicular lymphomas, 3 suggestive of lymphoma, and 1 unclassified B-cell lymphoma. Lymphoid neoplasms manifested in older people (mean age, 64.7 years) as a solitary mass in the pancreatic head, mimicking primary carcinoma. Clonality was confirmed by flow cytometry in 11 cases and immunohistochemical analysis on cell block material in 2. Obtaining diagnostic material often required several passes (average, 3.9 passes; range, 1-8 passes). We conclude that primary pancreatic lymphomas rarely are diagnosed by FNA, tend to be high grade, and clinically and radiographically might mimic primary carcinoma.