Amiodarone, Hyperthyroidism, and Small, but Growing Nodule

[ggmtscw]

Greetings,

My background:

Routine thyroid blood test by cardiologist regarding Crestor, etc. in Aug '12 reveals TSH 0.02, T4 1.9. T3 OK at 4.6 (little high): so, hyperthyroid. Primary care physician orders ultrasound and comes back with slightly enlarged right lobe and two nonspecific nodules, larger being .9 cm. PCP sends me to Endocrinologist - first appointment is early September. She looks over the paperwork and puts me on methimazole 10mg daily, says they don't normally biopsy anything under 1 cm and says I can't do an iodine uptake because I've been on amiodarone (for four years), which she says is likely the underlying cause of the problem.

We set a followup for three months or so which happened last Thursday (1/20). I stopped taking amiodarone immediately in September. No ill effects thus far. Result at followup last week is that I'm now hypothyroid, so methimazole is reduced to 5 mg daily. New ultrasound shows larger nodule is now 1.2 cm ("slightly" irregular). Biopsy is now scheduled for Jan 4 '13.

I'm having some intermittent minor neck pain on the right side (the affected lobe). Nothing unbearable, but irritating and concerning to me. No difficulty swallowing, but I can feel an ever-so-slight pressure when I'm laying down. Nodule is not visible: I can't even find it by palpating. Right side of neck seems slightly larger than left.

My questions:

- Is nodule growth reliably and accurately measured with ultrasound?

- If it is, then is growth of a nodule from .9 cm to 1.2 cm in four months' time a concern in the presence of the amiodarone-induced hyperthyroidism?

- Are there other symptoms I need to watch out for?

- What's the prognosis for amiodarone-related thyroid problems assuming one quits using it as I have?

Thanks so much in advance.

[Mark Lupo, M.D.]

Amio will stay in system for 6 months or more.  The nodule may be an area of inflammation (one common reason for amio induced hyper is thyroiditis) but the FNA is appropriate to confirm.  Prognosis in a mild situation like you describe is good for amio induced hyper.

[ggmtscw]

Thanks.  Your comment was a very nice Christmas present!  Happy Holidays.