The child with a neck swelling

Kayleigh is a 13-year-old girl who has recently noticed a neck swelling. Please examine her.

Stage: 10 of 13

You are shown her TFT results:

Free thyroxine (free T4) 30 pmol/L [10-20]

Thyroid-stimulating hormone (TSH) 0.01 mU/L [0.03-4.00]

Thyroglobulin autoantibodies - present