It would be interesting to know if the patient has other features of thyroid disease,e.g. goitre or other features of Graves disease. The results appear to be in line with hyperthyroidism, rather than simply analytical problems/drug interaction.  The negative anti-TPO and negative I-131 scan ( assuming this refer to thyroid uptake) are typical of thyroiditis. However, a small number of patients with hyperthyroism (clinical and biochemical) do have a 'normal' uptake.Are there also abnormalities indicating non specific changes on acute/subacute illness?

Hyperthyridism, of course, may not respond to Carbimazole (CBZ). I am not sure of the dose given and the duration (?4 weeks). A higher dose of CBZ or change to propythiuracil is another option. In resistent cases steroids have been tried and reported to induce a remission (report last 1998/199) in PGMJ, though I have no personal experience of this. If the clinician is happy with diagnosis of hyperthyroidism he/she could  consider RA-iodine therapy with anti-thyroid pre and post RAI. If all fails, and surgery deemed to be the only option then treatment with iodine prior to thyroidectomy could be considered.

hope this is useful.
Ahmed Waise FRCP FRCPath
Cosultant Chemcial Pathologist
Friarage hospital,
Northallerton, North Yorks

Tel 01609 763030
Fax 01609 764632
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