A thyroid biopsy is done by inserting a thin needle, using a needle with a special tip or making an incision to obtain a small tissue sample from the thyroid gland, explains WebMD. Doctors examine the sample under a microscope to determine the presence of thyroid problems.
In a fine-needle biopsy, a doctor uses a thin needle that passes through the skin and enters the thyroid gland, states WebMD. In a core-needle biopsy, a needle with a special tip is used to acquire a tissue sample with the size of a rice grain. A needle biopsy doesn't require anesthesia and allows the patient to be awake during the procedure.
An open biopsy involves creating a cut through the skin, allowing the doctor to view the thyroid gland, says WebMD. Physicians typically perform an open biopsy when other tests failed to determine the cause of a patient’s symptoms. A person is given general anesthesia during the procedure.
The purpose of a thyroid biopsy is to discover the cause of a lump in the thyroid gland or the cause of a goiter, notes WebMD. To prepare for the procedure, a patient should inform her doctor about any regular medications she’s taking, drug allergies and bleeding problems. Blood tests are sometimes performed to determine if an individual has a bleeding issue or a blood-clotting disorder.