large complex cyst on thyroid during pregnancy

[Amallory]

Hello,

Five years ago I found a nodule on my R thyroid and had a FNA which showed clear liquid.  No other tests were done at the time.  Now that I'm pregnant I recently had an ultrasound done and it shows that it is now a mostly solid 3.4 cm complex cyst with calcification.  They also found a smaller nodule on the left side.  I'm being sent for an ultrasound-guided FNA biopsy.  I'm 36 years old and currently 4 months pregnant and concerned about what treatment options are acceptable during pregnancy.  If the nodule is found to be malignant is it OK to undergo surgery?  Will I have to have radiation treatment at some point?  Can I delay the surgery until after the birth?  If the cyst is benign, how often should I be having it checked?  The doctor I am seeing seemed puzzled that I hadn't had an earlier US (5 years ago) to allow for comparison of size over time.  Should I be having regular US and FNA?

Thanks in advance for your advice.

[joanelwine]

A related discussion, large congenital cyst on thyroid was started.

[hbmomx1]

I have 4 thyroid cysts that are being treated with Levothyroid (high doses) to shrink them.  I have thyroid scans every six months and blood work every 2 months.  The reason being is that my TSH level shold be pretty much non-existant so that the cysts don't continue to grow.  There is a test that check for a certain antibody, I forget the name of it, but talk to your physician preferably an endocrinologist and they will know what to order.  If you will require surgery than yes 2nd trimester is the best for the baby...good luck

[Mark Lupo, M.D.]

If it's malignant, it's okay to wait until after delivery in most cases unless the FNA suggests an aggessive cancer (ie anaplastic) OR the mass is growing rapidly.  If surgery required, best to do 2nd trimester.  If it's cancer, radioactive iodine MAY be indicated but not always.  If it is benign, repeat every 6-12 months depending on the situation.  Sounds like a benign complex cyst.

[m300]

Most nodules/cysts should be checked periodically for changes in size.  I am surprised the doctor who diagnosed you 5 yrs ago didnt recommend to recheck atleast annually.  

I would think your doctor would wait until after birth to do such a surgery as most thyroid cancers are not aggressive.  but I would take things one step at a time and have the biopsy and take things from there.  95% of these things are benign.  But you have to test for sure.

And even if malignant, most thyroid cancers stay contained in the thryoid and dont spread.   Very few people would need radiation.  Most peope take a radioactive medicine after removal of the thyroid to ensure it is all gone and doesnt come back.

I just had mine out last month.