I came across this excellent summary of Thyroid nodules from the American Association of Endocrine Surgeons which links to a similar European one.  It confirms much of what I wrote in my blog post “Troublesome Thyroids” in regard to my own thyroid issues.  I’m thankful to the AAES for promoting this on social media. 

I wanted to focus on the issue of Thyroid nodules given I see these mentioned all the time in my online patient group.  Clearly, when you already have a cancer diagnosis, the discovery of more issues on top of that is of concern to patients. Many are incidental and only found because of imaging following the cancer diagnosis.  This is an important point because an average of more than 50% of people over the age of 60 have thyroid nodules and around 90% are benign.  In a 60+ year old person (a large proportion of the Neuroendocrine Cancer patient population), the discovery of a thyroid nodule is potentially the most common incidental finding.

What is a thyroid nodule?

A thyroid nodule is a growth within the thyroid gland. Thyroid nodules are extremely common. Studies have shown that the chance of having a thyroid nodule increases with advancing age e.g. up to 70% of women over the age of 60 years may have a thyroid nodule and up to 30-40% of men. Common methods of detection include self-discovery, palpation on physical exam, or incidentally on an unrelated imaging study (carotid ultrasound, CAT or PET scan, etc). Most are asymptomatic, but when large, can cause obstructive symptoms (dysphagia, shortness of breath, cough, OSA, etc.. ). Most are benign – the risk of cancer ranges from 5-15% based on certain risk factors and ultrasound characteristics. Not all nodules need a biopsy, and proven benign nodules no longer require a lifetime of follow-up (although they may opportunistically keep an eye on them within existing NET surveillance). See below for further details and workup and management.

What are the risk factors for thyroid cancer?

When a patient is diagnosed with a thyroid nodule, it is most important to rule out thyroid cancer. There are several factors that may increase the risk of having cancer. These risk factors include:

• family history of thyroid cancer or thyroid cancer syndromes (MEN, Cowden’s, FAP, Garner’s, Carney complex, CHEK2)
• personal history of radiation to the head, neck, or upper chest
• age < 20 years or > 70 years
• nodules that are more rapidly increasing in size
• nodules that have a hard consistency
• enlarged neck lymph nodes
• symptoms of persistent hoarseness

Evaluating a Thyroid Nodule

Very often, thyroid nodules are asymptotic but some people may have signs and symptoms, e.g. notice a fullness in the neck below the Adam’s apple, experiencing difficulty swallowing solid foods, or have a sense of pressure in that area.  Blood tests can be carried out to assess the impact on thyroid hormone levels, e.g. TSH, T3 and T4.

An ultrasound (US) is the best study to evaluate the thyroid and the neck area. Some special US machines also have the ability to perform elastography, which measures the stiffness of a nodule (with stiffer nodules being more likely to be malignant). Depending on the US findings, a thyroid uptake scan could be done to see if the nodule is hyperfunctioning.   Radiologists have a scoring system in an attempt to standardize the reporting of thyroid US images. There is conflicting data regarding the accuracy of TI-RADS due to interobserver variability, and also when compared to surgeon and/or endocrinologist-performed thyroid US.  But I leave you with this reporting standard below:

TI-RADS 1: normal thyroid gland

TI-RADS 2: benign lesions

TI-RADS 3: probably benign lesions (<5% chance)

TI-RADS 4: suspicious lesions with increasing risk dependent on the number of suspicious features

• • solid component
  • high stiffness of nodule on elastography if available
  • markedly hypoechoic, microlobulations or irregular margins
  • microcalcifications
  • taller-than-wider shape

TI-RADS 5: probably malignant lesions (> 80% risk of malignancy; has all 4-5 of the above features).

Please note the TI-RADS categories are not the same as the biopsy standard and although it looks like there are similar meanings in comparison, it should not be assumed there is a direct 100% correlation between the two.

Biopsies

The introduction to this summary indicates not all nodules need a biopsy.  When required, however, fine needle aspiration (FNA) is the most common.  In my own case, several FNAs were done but not enough was found.  A core biopsy (bigger needle) was eventually carried out but produced an inclusive score.  Mine was categorised as a THY3 (see categorisation standards below).  USA uses a ‘Bethesda’ 1 to 6 category system while in UK they use a ‘THY’ 1 to 5 equivalent.   Other countries may use one of these or their own variant, e.g. see the Italian system below alongside.  The diagram below is provided by the European Thyroid Association but contains a typo in that THY3b should read THY3f. 

Summary

I hope this has been useful for those who have been told they have a thyroid nodule.  It would seem for most; this is a minor issue. But notwithstanding statistics, I understand the worry this might bring but see the risk factors above.

I have had personal experience of this, and my problem has not yet gone away, still under surveillance.  I attached my two thyroid-related blog posts below.