--makes sense; autoantibody positive hypothyroid conditions can cause irregular tissue formations (i.e, lumps, goiters) that might be taken for malignancy until there's a more detailed and up-close tissue examination.

My wife had recently been diagnosed with autoimmune thyroiditis--I called it early on, as nobody who is always cold, has dry skin/hair, a slowly rising TSH number, and who has gained 15 pounds in 18 months despite running 55-60 miles a week should go without a metabolic check-up. Antibodies were found in serum testing; fortunately a thyroid ultrasound appears "normal". She's now on 25mcg Synthroid each day and will be checked frequently for horomone levels and to see if said dose needs adjusting.

Autoimmune hypothyroidism is a pain--but much better than having a malignancy, of course, and it is treatable. What are they doing for you in that regard?