Hyperthyroid w/Hashimoto's mistaken for Graves?

[unexpected]

Hi Dr Lupo,

I was feeling fine and had a routine physical a little over a month ago, when the following turned up in my lab results:
T4 (Free) 2.1 (normal range 0.8-1.8)
TSH <0.01 (normal range 0.4-4.5)

I got retested along with some thyroid antibodies, and got the following results:
T4 (Free) 2.5
TSH <0.01
Thyroid Peroxidase AB: 304 (normal < 35)
Thyroglobulin AB: 126 (normal < 20)

Obviously hyperthyroid, which is strange because there is no history of hyperthyroidism and/or Graves Disease in my family. However, there is some history of Hashimotos Disease. I know that normally HD would make me hypo, but I've read that there are short periods where you can be hyper.  I am asymptomatic as far as I can tell (I feel fine), though my endocrinologist notes that my gland is 1.5x the normal size. My endocrinologist has scheduled more bloodwork to get a T3 reading and radioactive iodine uptake/scan of the thyroid to determine if it is cause by a virus or GD, but I'm wondering if these tests can determine whether it's GD or HD, or whether I should have further testing done on my AB , or something else to determine whether its caused by Graves or Hashimotos.

[Mark Lupo, M.D.]

You have autoimmune thyroid disease - with the increase in T4 over a one month period, this is not likely thyroiditis (ie, "virus") - a family history of Hashi (also autoimmune thyroid disease) increases the risk for any autoimmune thyroid problems -- this is most likley Graves Disease.  Additional testing to cofirm would be the uptake/scan as well as TSI/TBII antibodies.

[jerrysgirl]

hil, my comment to you about tdh, i stand corrected, it is fdh, not tdh, (familial dysalbuminaemic hyperthyoxinaemia)

[jerrysgirl]

funny i should find this today  15 years ago  was told i had ggraves diesese  was told i needed to have thyroid zapped (kill) with radioactive ?????(right wording isnt coming to me)anyway  went to have this done and was told thyoid burned out by itself..then was told a few weeks later it hadn't burned out...to make a long story short,, even the endocronolist was stumped because of tsh, free t4 t3 were very conflicting....was sent to National institute of health because now it was thougjht i had this childhod stunting thyroid problem,,,,,was to find out i had hasimotos, along with another rare thyroid problem called tdh,  ( in the past graves diesese is what dr. thought sojme of their patients had, ) but with thime discoverys were made that the tdh along with hasimoto looked to dr. as if the diagn....was gravess.....  hope this can be something you can speak with your dr.  about and comes as some help;;;