Fine Needle Aspiration Cytology (FNAC) is a simple and quick diagnostic procedure used to investigate lumps or masses in the body. A thin, hollow needle is inserted into the mass to extract a small sample of cells for examination under a microscope.

FNAC is commonly used to evaluate swellings in the thyroid, lymph nodes, breasts, and salivary glands. It is a minimally invasive, cost-effective, and accurate method to determine whether a lump is benign or malignant.