THYROID INVESTIGATIONS

 Fine needle aspiration cytology (FNAC)

A small needle (smaller than that used for blood tests, for example) is put into a thyroid lump or nodule and the cells that are drainedaway are examined (cytology). I most usually do this under ultrasound guidance for increased accuracy and for the imaging information. This can diagnose acancer in a thyroid nodule, or (preferably) prove that a benign thyroid lump is just that-benign and non-cancerous. Sometimes it is not possible to come to a diagnosis and an operation may be necessary.

Ultrasound scan

This is the main form of imaging of the thyroid gland. Italso enables the clinician to perform FNAC more accurately (see above). I have been performing large numbers of thyroid and neck ultrasound scans since 2002 and do it at the time of consultation.

Other scans

Other scans include CT, MRI and isotope scans. These do not have much of a role in routine thyroid investigation in the modern era.

Flexible laryngoscopy

This involves examining the throat and voicebox via a fibre-optic endoscope (small tube) inserted through the nose. It causes minimal discomfort. It is done to see if there is a vocal cord paralysis. This is important to know when assessing a lump in the thyroid gland because it can suggest malignancy. It is also important to know of any paralysis before thyroid surgery. The second main reason for this is as part of investigation when a patient has a goitre and has compressive throat symptoms, in order to see if there is anything else to explain the throat symptoms (rather than just assuming it is due to the goitre).