Fine needle aspiration.

Fine needle aspiration (FNA) has been widely used as a diagnostic tool for the past half century. Differing from large bore cutting needle biopsy, FNA utilizes 22- to 27-gauge needles. The cell samples aspirated from a lesion are characteristically smeared on glass slides for immediate microscopic evaluation. An adequacy report and a preliminary diagnostic impression are rendered in approximately 10 to 15 minutes. A final report is generally rendered within 24 hours. The method has been used as one of the most cost-effective, complication-free, and rapid techniques for preoperative investigation of tumors and tumor-like conditions. Its usefulness in the diagnosis and management of oncology patients is emphasized in this article.