Needle biopsy/FNAC is a medical test performed by interventional Radiologists/Radiologists to identify the cause of a lump or mass, or other abnormal condition in the Thyroid gland.

During the procedure, the doctor inserts a small needle, guided by USG, CT or other imaging techniques, into the abnormal area.

A sample of tissue is removed and given to a pathologist who looks at it under a microscope to determine what the abnormality is — for example, cancer, a noncancerous tumor, infection.