The first step is to determine whether the nodule is malignant or benign. This is determined by using fine needle aspiration cytology (FNA). In this test, a very fine needle is inserted into the nodule and a few cells removed for the cytologists to study. The cytologist then determines whether the nodule is benign or malignant.It must be rembered that cancer of the thyroid is not limited to solitary nodules of the thyroid and has a significant incidence in multinodular goitre.
FNA ofthe thyroid is discussed in detail in the introduction section to thyroid surgery
In the USA anultrasound scan is performed to look atall patients with a thyroid nodule and the fna is performed under ultrasound control. This practice is not considered mandatory in the UKand theguidelines of the British ThyroidAssociation suggest that ultrasound in these circumstances is merely helpfulin doing the fna and can demostrate other nodules.Mr Lynn has all thyroid nodules subjected to an fna under ultrasound control.An ultrasound scan cannot give a definitive answer as to whether a nodule is benign or malignant, but it can show characteristic features such as coarse calcification,comet tails or the prescence of a very distinct margin all of which suggest the nodule is benign.
Cystic thyroid swellings are less likely to be malignant than solid swellings.Cystic lesions in men are more likely than in females to be malignant.Krukowski's unit in Aberdeen published in 2008 that recurrence of cysts even with a THY2 cytology is an indication for surgery as 54% of patients with THY1/2cytology are cancerous.