Fine-needle aspiration cytology of Kikuchi's lymphadenitis: a report of ten cases.

The purpose of this study was to evaluate the cytologic features of Kikuchi's lymphadenitis (KL). Smears from 10 patients with histologically proven KL were reviewed. In all cases, fine-needle aspiration (FNA) was performed prior to biopsy. To assess the validity of morphologic recognition, a blinded study, including smears from non-Hodgkin's lymphomas, nonspecific, and mycobacterial lymphadenitis was performed. At least 5 cases showed characteristic cytologic findings that permitted their specific recognition. A polymorphous lymphoid population with abundant karyorrhectic debris and histiocytes, many of which showed a small size and eccentrically placed, crescent nuclei, were characteristic features of KL. The remaining 5 cases failed to show typical findings and were indistinguishable from other nonspecific, reactive lymphadenopathies. When typical cytologic findings are present in an adequate clinical context (cervical nodes in young patients), a precise diagnosis is possible, avoiding unnecessary biopsies.