Ultrasound Results Question

[Msmustang1981]

Hello,

I just had my annual thyroid ultrasound. Last FNA was last year and benign but my doctor likes to get eyes on the thyroid nodules annually and the one on the right is now non-existent compared to last year, leaving just the left nodule. This is the first time the report shows a shrinking thyroid and it scared me. What does this mean? I’ve never tested positive for Hashimoto’s, but I know I can have it without testing positive. I’ve been on T3 only for the last 5 months… can this cause shrinking thyroid? I also got lab work done today, so waiting on those results, but I do feel overmedicated. Ultrasound report below. Thanks for help understanding this.

EXAM: THYROID ULTRASOUNDCLINICAL INFORMATION: History of thyroid nodule.

COMPARISON: Ultrasound dated 6/22/2021. FNA dated 8/12/2021.

INTERPRETATION: The right lobe measures 1.7 x 1.1 x 4.2 cm, the isthmus measures 1 mm in thickness and the left lobe measures 1.6 x 1.1 x 2.8 cm. Thyroid volume 6 cc (normal female volume 10 to 15 cc).A solid nodule in the left lobe measures 9 x 7 x 14 mm, unchanged. It was previously aspirated with benign results.

TI-RADS: Solid, 2 points, isoechoic, 1 point, wider than tall, 0 points, smooth margins, 0 points, no calcifications, 0 points, total 3 points, category TR3, mildly suspicious.Normal echotexture. No other mass.

CONCLUSION: 1. Stable left lobe nodule. Benign on prior FNA. 2. Small gland, likely related to chronic thyroiditis.

[radd]

Msmustang1981,

T3 meds alone won't cause thyroid gland shrinkage. The gland shrinks slightly with age anyway but another common reason is Atrophic Thyroditis (Ords) defined by the presence of TBAb’s which are more common than people think, even in the presence of Hashi. It’s just they are rarely tested because few labs have the ability to do so, and aren’t considered in primary care.

If we don't use it, we lose it and the definition of Ords is ‘a thyroid gland volume of 5.0ml or less, and without goitre’ but of course if you have also suffered TPOAb’s at some point a goitre is possible. Also cysts and the numerous lumps & bumps caused indirectly by the push/pull of various autoimmune attacks.

In order to convert further FT4 -FT3, TSH will up-regulate D2 enzyme activity but when TSH is blocked by these high TRAb levels FT3 levels can reduce quite substantially, even in the presence of normal RT3 levels. Tania Smith says TBAb’s are prone to severe fluctuations and a large high can block more than 98% of TSH receptors no matter how much is in circulation. This can make TSH raise in response to blocked TSH receptors. Either way, yet another reason not to diagnosis (or dose meds) according only to a TSH level.

You mention feelings of being over-medicated but your next posts labs don't show FT3 over range, and considering your past thyroid hormone needs it would be unlikely that 30mcg T3 would tip you over but if you were to presently have fluctuating antibodies, then both or one thyroid hormone could go to extremes in either direction.

Also raised liver enzymes in your recent past post is a classic system of inadequate thyroid hormone so maybe you either aren't medicating enough thyroid hormone (ie need FT4 raising) or the T3 you are taking isn't working on a cellular level. Remember these labs are only what is circulating in the blood and there is no guarantee of them working as they should.

Medicating Levo (or NDT) gives us window to miss a few days of meds when feeling over medicated but because of T3's short half life if I were you I would just half the dose for a few days and increase back up in 5mcg increments slowly. Whether antibodies have made an initial attack or a reoccurrence you may need to keep FT3 lower with the steadiness of some background Levo(or NDT) adding whilst hormone levels risk being erratic, and now your adrenal insufficiency is treated you may find better Levo tolerance anyway. Ensure to keep iron levels optimal too.

[Msmustang1981 in reply to radd]

Thank you very much for your thoughtful and thorough reply! I really appreciate all of the details.