What does it mean when TSH and FT4 are elevated but antibodies are neg?

[Momtoclay]

13 y/O female with JRA and Family history of thyroid disease and thyroid cancer. Normal thyroid labs from birth to 2011.
Dr noted swollen cervical glands and possible enlarged thyroid on exam. Sent for ultrasound of thyroid and thyroid function studies.
U/S showed mildly heterogeneous appearance of right lobe

[Mark Lupo, M.D.]

The borderline high TSH and heterogeneity on US, along w/ h/o JRA and family history all point towards Hashimoto's despite negative TPO/TG antibodies.  If she is on immunosuppressant for JRA, the Ab's may appear normal.  If she is having symptoms, then a trial of low-dose levothyroxine may be reasonable.

[Momtoclay]

Dr Lupo,
Thank you for your previous comment on my question. I have a follow-up question if you have time...
Our appointment with Endocrine is still a ways off (mid November). My daughter had her yearly physical/well check 4 days ago. she had a very low heart rate in the doctors office (47 bpm) it was 3:30pm. Dr sent her for ECG and that was done today around noon, it showed "Marked sinus bradycardia and sinus arrhythmia" her heart rate was 48 there were a lot of other numbers on the report but I could not get a copy of it because it had not been sent to the pediatrician yet. They were faxing it over to pedi and to a pediatric cardiologist to be read. I have not gotten a call from the pedi yet.
My question for you is: Can this be related to her thyroid issues?

her TSH and fT4 were both elevated (very mild elevation on both numbers I think). She has been fatigued, had some issues with circulation in her extremities (tingling and numb sensation in feet, very cold hands and feet, and also had some pretty bothersome restless leg issues over the last 6 weeks or so) I know athletes can have lower HR and it is nothing to be concerned about, its actually a sign of good health if I'm not mistaken. While she does like to play sports, and is thin. I'm not sure that qualifies her to have this "athlete low heart rate" status. Her pedi did run some labs: re-ran thyroid panel, CBC, Chem 20, lipid panel, vit D and VIt B12 we should get those results tomorrow.

[Momtoclay]

Thank you. She IS taking methotrexate for the JRA. Has been on 15mg orally once per week for 17 months. Also taking Rx folic acid, 20 mg nexium, and voltaren daily.
She is having synptoms that appear to be associated to hypothyroid, however it's hard to know for sure since she also has the JRA. But some symptoms she has been experiencing  over the last 6 months or so; increased h/a, fatigue, muscle aches and cramps, temperature issues ( she is either too cold or too hot and can't seem to get comfortable. Restless leg, chest pains, and ear pain ( she has been checked for ear infection three times over the last 6 months but has not had in, but her ear hurts)
She tries very hard not to let any of this get in her way and remains very active in her favorite sports. However we are seeing more injuries (1 stress fracture, 2 muscle strains, 1 hip flexor strain all in the last 6-9 months) over the past ten days or so she has been having almost constant tingling/pins and needles in her feet and hands.
She has also had a nagging cough (not productive cough, more like a dry cough) for three months. Her pedi actually put her on an inhaler last month because of the shortness of breath.  But this is not a sickly girl. Most of these issues are just nagging or bothersome she works very hard not to let them get in her way.
The Endocrine clinic called and will see her in November. That seems a little far away to me. Should I talk to her pedi about a possible trial of levothyroxin? Or will that get in the way of a proper exam and diagnosis by the endo in Nov.? I hate for her to have to deal with these health issues and possibly get worse for three months into the school year. But I also don't want to take any chances that we don't get this figured out with the proper  specialists.  Is 3.5 months an appropriate amount of time to wait for a work up on this issue?

[Momtoclay]

I got the other labs from the pedi office, the autoimmune tests were:
thyroglobulin ab  <20 (0-40)
thyroid Perox ab  7  (0-26)

[Momtoclay]

(continued)
And a singular cyst or nodule 5mm in the left lobe.
TSH 4.83 (.4-4.5)
FT4 1.75 (.6-1.5)

Thyroid antibodies labs were negative according to her doctor( I did not ask for any numbers or specific results for these tests- not sure if there are any or if it's just a pos/neg result?)

She does have some hypothyroid symptoms, fatigue, pins and needles in extremities, cold intolerance (also heat intolerance) but is very thin.

The cyst or nodule found is under 1cm so would not normally require FNA correct? What do the labs mean? Does she possibly need the FNA due to her age and family history?
Our Pedi Endo clinic is super busy and tend not to be interested unless your child is growing a third eyeball or has a TSH of 88. I have a feeling we will be considered a routine case and not be seen for 6 months. My question is- is that okay? Is this routine? Or should I be assertive about getting her in sooner? Possibly try to get her into a non-pediatric endocrinologist ( which would happen much quicker). I can call her Rheumy doc and get a little assistance getting into endo sooner, but I don't want to do that if this is actually something that can wait. I just don't understand these labs and if course don't like seeing the nodule no matter how small. So I don't know what to do?
Please advise.
Thank you!