Consultant Head and Neck, Thyroid Surgeon


This is the most important test and should be performed on almost all thyroid lumps. Fine needle aspiration involves removing a few cells from within a lump for microscopic examination using a small needle. The test is done in the clinic and provides a rapid aid to diagnosis. Examples of cells taken in this way are shown below. cytpics1-2

Following assessment a thyroid lump can be categorised into five groups called the Thy Classification:


Thy 1. Non-diagnostic - no clear answer on biopsy.  Biopsy should be repeated.  If persistently in this category serious consideration should be given to surgery.

Thy 2. Benign

- the lump can be safely left alone.  National guidelines in the UK are for a second biopsy 2-3 months later as a a final check.  Some patients will opt to have benign lumps removed because they are causing problems.

Thy 3. Indeterminate - this category is usually due to a type of growth of the thyroid gland.  Lumps in this category are usually benign but approximately 15% are malignant.

Thy 4. Suspicious - cells are suspicious of malignancy.  Most of these lumps will be require a second biopsy and ultimately surgery.

Thy 5. Malignant - cells and features seen consistent with thyroid malignancy.  This is usually papillary thyroid cancer but other rarer types can be identified e.g., medullary or anaplastic.
Fine Needle Aspiration test?