Do positive thyroglobulin antibodies suggest recurrence of papillary thyroid carcinoma?

Hello,

Welcome to icliniq.com.

I understand your concern. I have reviewed your reports (attachment removed to protect the patient's identity). 1. Post-operative histopathology suggests unifocal (restricted to one site) papillary carcinoma of the thyroid gland without lymph node metastasis which suggests an excellent outcome after surgery. 2. A post-operative radioiodine scan showed a small remnant of normal thyroid tissue (it seems to be normal uninvolved tissue as histopathology could find d completely excised tumor). If there is a small remnant left, then it is expected that thyroglobulin levels will increase once the suppressive dosage of Levothyroxine is reduced during pregnancy. 3. Thyroglobulin is produced in the presence of normal thyroid tissue and is not suggestive of thyroid carcinoma per se. So it can be derived that a reduced dosage of Levothyroxine during pregnancy has led to stimulation of normal remnant thyroid tissue leading to an increase (very minimal) in thyroglobulin level. 4. Once you increase the dosage of Levothyroxine to 150 mcg, thyroglobulin levels will decrease and will again reach levels seen before pregnancy. Considering all these points, the chances of recurrence are minimal, and there is no reason for concern. I hope this helps. Thank you.

Hello,

Welcome back to icliniq.com.

Anti thyroglobulin antibodies are autoantibodies due to Hashimoto's thyroiditis. In some cases, there may be autoantibodies for papillary carcinoma though there is no reliable evidence. High TgAb levels can interfere with Tg levels and can falsely reduce Tg levels during routine postoperative follow-up. In your case, since there was remnant functioning thyroid tissue as per the radioiodine scan, it is expected that the levels of TgAb will be high during follow-up, which may not necessarily suggest tumor recurrence; rather, it may mean functioning normal thyroid tissue. However, serially increasing TgAb levels above 100 IU/mL is a matter of concern and warrants workup for recurrence. As of now, I suggest you take Levothyroxine 150 mcg and get the tests repeated after a few months.

Hello,

Welcome back to icliniq.com.

Any change in Levothyroxine dosage during breastfeeding must be done after consulting your pediatrician. An increase from 12 IU/mL to 17 IU/mL is not significant. An increase in Levothyroxine dosage probably will suppress both Tg and TgAb levels.

Hello,

Welcome back to icliniq.com.

There is reasonably good TSH suppression with 100 mcg. You can continue the same dosage for the next six months. Recurrence does not usually occur by just reducing the dosage, as you had a unifocal lesion with minimal chances of recurrence.

Hello,

Welcome back to icliniq.com.

TSH levels are supposed to reduce with a higher dosage of Levothyroxine. Your TSH levels are considerably low already. So dosage change probably has not made much difference. TSH is a stimulating hormone produced by the pituitary gland. Its levels do not suggest a thyroid tumor. Tg and TgAb levels are more critical, and TSH levels should always be lower than normal.

Hello,

Welcome back to icliniq.com.

Even a small remnant of normal thyroid tissue is sufficient to produce Tg and TgAb. Post operative radio iodine ablation does not guarantee permanent ablation. That is the reason TSH suppression is important after surgery. Your lymph nodes were negative in histopathology report. So I do not think there is any chance for lymph node metastasis at this stage. Your TSH levels do not affect your baby as it not secreted in milk in significant quantities. Babies produce their own TSH and can very well maintain their thyroid function. You need to consult a pediatrician before increasing your dosage of levothyroxine while breastfeeding. I hope this helps. Thank you.

Hello,

Welcome back to icliniq.com.

Your latest ultrasound report suggests the presence of lymph nodes in level 2 of the neck, without any ultrasound signs that suggest metastatic nodes. These nodes are very likely reactive, possibly due to a recent upper respiratory tract infection. I recommend getting another ultrasound in three months to compare their size. If there is an increase in size, a repeat radioiodine scan will be necessary to determine if they are metastatic nodes. However, for now, I do not believe any further action is required.

Thank you.

Hello,

Welcome back to icliniq.com.

As I mentioned earlier, these nodes appear to be more indicative of reactive lymph nodes, and it is unlikely that they will require any additional evaluation. The previous scan confirms this. Nonetheless, it is essential to continue with serial scans every six months for the first five years after surgery.

Thank you.

Hello,

Welcome back to icliniq.com.

A significant increase in size will make them noticeable and palpable. Papillary carcinoma in its early stages, when treated appropriately (as in your case), has an excellent prognosis, and the chances of recurrence are very rare. Both scans have commented on the same nodes, and there are no new nodes that have enlarged.

Thank you.

Hello,

Welcome back to icliniq.com.

The baby would not require any scans. Generally, a thyroid function test (T3, T4, TSH) is performed once in the initial period to check for any changes and is usually not repeated if the results are normal.

Thank you.