A 52-year-old female presents with tiredness


A 52-year-old female presents with tiredness.
There are no specific abnormalities noted on examination, but investigations reveal:
T4 21.1 pmol/L (10-22)
T3 5.2 pmol/L (5-10)
TSH 0.05 mU/L (0.4-5)
Thyroid autoantibody titres are all undetectable.
Which diagnosis do these results suggest?

De Quervain’s thyroidits
Graves’ disease
Hashimoto’s thyroiditis
Sick euthyroid syndrome
Solitary toxic nodule  This is the correct answer

This patient has subclinical hyperthyroidism and, in the absence of thyroid auto-antibodies, the most
probable explanation of these thyroid function abnormalities is a solitary toxic nodule.