neurofibroma of the thyroid gland

I have neurofibromatosis (NF1) and recently had a sonagram of my thyroid and they found numerous "places" on my thryoid.  They did a fine needle biopsy and they came back benign.  My endocrinologist doesn't think this is related to my neurofibromatosis, but I think it is.  Should I get another opinion?  I am scared to just leave these alone and do nothing.  I have also been on synthroid 125 for over a year and my levels are still not going up like they should.

[Neuro Forum]

Thanks for using the forum. I am happy to address your questions, and my answer will be based on the information you provided here. Please make sure you recognize that this forum is for educational purposes only, and it does not substitute for a formal office visit with your doctor.

Without the ability to obtain a history from you and examine you, I can not diagnose the nature of your thyroid problem nor its management. However, I will try to provide you with some information regarding this matter.

If your fine needle biopsy shows benign findings, then this is reassuring. However, it is important to keep in mind that in a very small percentage of patients with NF1, a specific type of cancer of the thyroid can occur called medullary thyroid carcinoma. Again this is rare, but an association between the two conditions has been described. Please understand I am not trying to imply I think you have thyroid cancer, but only that in patients with NF1, this needs to always be excluded, and the most important thing is regular follow-up of any thyroid region (serial examinations and surveillance). However, more commonly, thyroid lesions are benign, even in NF1 patients.

I recommend close follow-up with your neurologist and other physicians; evaluation if possible at a center that has a specialized multi-disciplinary center for neurofibromatosis may be useful to you (because their physicians would have expertise in this area).

Thank you for using the forum, I hope you find this information useful, good luck.