Department of Endocrinology, St. George's Hospital, London, UK.
A 32 year old women presented to her G.P.with a four month history of a lump in her neck, weight loss and anxiety. She had hyperthyroidism (TSH <0.1 mU/l, fT4 >100 pmol/l, TPO antibodies 318IU/ml). Thyroid U/S showed a 2x3cm nodule in the right lower pole. A thyroid isotope scan was reported as showing increased uptake throughout the gland with an area of decreased uptake in the right lower pole. She was started on carbimazole 30mg o.d. and she was referred to a head and neck surgeon who performed fine needle aspiration cytology of this lesion. Cytology suggested a follicular neoplasm with the possibility of follicular variant papillary carcinoma. She underwent a total thyroidectomy. Histology showed hyperplastic papillary structures mimicking papillary carcinoma but without any of the pathognomic nuclear features.
Recent prospective studies have suggested that the prevalence of clinical thyroid cancer is increased in patients with Graves' disease (1.3-1.9% vs. 0.15-0.2% in the general population). There is also some evidence of increased aggressiveness of thyroid cancer in Graves' disease. As a result, some Italian and American authors have suggested routine U/S or technetium scan in all patients with Graves'. This has significant cost implications. The annual incidence of Graves is 2 per 1000 so in a local population of 300,000 there will be 600 new cases a year. Thyroid U/S and technetium scans cost £60 and £195 respectively. The cost of thyroid imaging in all Graves' patients would be £36,000 for U/S and £117,000 for technetium scanning per year. Our current practice does not include routine thyroid imaging for patients with Graves'.