Excising of thyroid

[diogenes]

This is just passing on what a doctor has told me. In surgical thyroidectomy, it is quite often the case that a small portion of the thyroid is left, and apparently the pituitary isn't sensitive to or affected by this small T4 contribution. With radio-destruction of the thyroid, this almost always results in complete thyroid loss. So post-surgical thyroidectomy patients may need more subtle attention to the existence of any working residue.

[bookish]

Is it likely that a partial thyroidectomy could have a similar, if proportionate, effect? Thanks

[diogenes Remembering in reply to bookish]

Yes, if any significant part of the thyroid is left, the remnant will put out more T3 at the expense of T4, because now the TSH now keeps the T3 part going by positive stimulation.

[bookish in reply to diogenes]

Thank you. Could this exhaust over time? My partial was 2011 but my FT4 now down to 2% of range and FT3 minus 9%.

[diogenes Remembering in reply to bookish]

So long as there is any significant thyroid tissue left, TSH will stimulate it to make T3 more preferentially than T4. Thhis will go on until perhaps only 5% of the tissue is left working. Then, the whole system collapses, and the patient is entirely dependent on T4 by mouth.

[bookish in reply to diogenes]

Thank you for that.

[humanbean]

In surgical thyroidectomy, it is quite often the case that a small portion of the thyroid is left

Is this deliberate? Or is it just a fact of life that removing all of the thyroid is difficult?

[diogenes Remembering in reply to humanbean]

It is not done deliberately, but surgeons don't want to excise the parathyroids as well, so that if the whole anatomy insists, leave a little thyroid tissue to be safe.

[humanbean in reply to diogenes]

Thank you.

[TSH110 in reply to diogenes]

I think I have read that even when attempts were made to remove all tissue some was still missed

[jimh111 in reply to humanbean]

Sometimes part of the thyroid may not be visible, it can e.g. be behind the windpipe or it can be very close to vocal cords. So, the surgeon may leave some tissue behind in order to play safe. In cases of thyroid cancer this is followed up by RAI.

In some cases it is deliberate, if e.g a goitre is being removed there's no need to excise good tissue.

[humanbean in reply to jimh111]

Thanks.

[SilverAvocado]

With my thyroidectomy for thyroid cancer this was talked about a lot. After the surgery I had radioactive iodine (RAI) treatment, followed by RAI scans to confirm there was no thyroid tissue remaining. Thyroid tissue takes in iodine more than any other, and a radioactive form of iodine exists, which makes all this work.

For the scanning dose, a smaller dose of RAI is taken, and the radiactivity can be detected by a scanner. After my surgery and first dose of RAI it seemed some of the thyroid may have grown back, as there was quite a bit visible on one of my scans. I did feel a painful burning sensation in my throat while it was destroyed by the radiation

The treatment dose is an inpatient procedure, you're kept in quarantine for several days. The RAI is always offered very dramatically. I had a pill delivered in a big lead lined case for my treatment dose, and for the scanning dose a glass of orange squash sucked up with a straw.

Mine was follicular cancer and fairly large, I think for some less advanced cancers the thyroidectomy alone would be offered.