Follow-up of morphologically reactive lymphoid proliferations in fine-needle aspirates of elderly patients

Fine-needle aspiration (FNA) is an effective tool in evaluating the cause o f lymphadenopathy While the morphologic diagnosis of a reactive lymphoid pr oliferation is common in younger patients, this diagnosis should be made ca refully in older patients (those over the age of 50 yr) in light of the fac ts that such purely reactive conditions occur much less frequently in this population, and that follow-up of these patients reveals a malignancy (usua lly lymphoma) in a significant number of cases. In this series, we identifi ed 40 patients with a morphologic diagnosis of reactive lymphoid proliferat ion on FNA and obtained their follow-up information. Of 19 patients under t he age of 50 yr, 5 underwent subsequent biopsies and only one revealed a de finitive malignancy (5%). In contrast, 7 of 21 patients over the age of 50 yr underwent a subsequent biopsy, and 6 were found to have a malignancy (5 malignant lymphomas, 1 metastatic melanoma). The higher rate of positive fo llow-up (29%) in this age group supports previous suggestions that morpholo gically reactive (mixed) lymphoid proliferations be viewed with increased s uspicion in the elderly patient, and that additional studies, such as flow cytometry, be performed when material is available. (C) 2000 Wiley-Liss, In c.