Needle aspiration of the thyroid gland is used to determine the cause of a lump and, if the lump is a cyst, to drain it. During the procedure, cells are removed from the abnormal area using a fine hollow needle attached to a syringe. Ultrasound guidance may be used if a lump is inaccessible. The sample is then examined in a laboratory for cancerous cells. This procedure is safe and almost painless and can be carried out in an outpatient clinic.
From the 2010 revision of the Complete Home Medical Guide © Dorling Kindersley Limited.