Lymph nodes fine needle cytology in the diagnosis of infectious diseases: clinical settings.

Lymph node reactive hyperplasia, caused by specific infectious etiologic factors, represents the most frequent cause of enlarged peripheral lymph nodes. The main infectious agents are viruses, pyogenic bacteria, mycobacteria, fungi and protozoa that may determine unspecific or specific pathological entities, such as cat-scratch disease, toxoplasmosis or infectious mononucleosis. Lymph node fine needle cytology (FNC) is a safe, simple, cost-effective and efficient technique that quickly provides information about the cell population and the nature of the process. FNC can also provide suitable material for ancillary techniques, such as flow cytometry, immunocytochemistry, molecular biology and microbiological examinations. This study focuses on the cytological features of benign lymphadenopathy of infectious origin and their possible contribution to the clinical setting definition of corresponding patients.