Although overt thyroid disease is easily recognised, lesser disturbances of thyroid function can prove difficult to diagnose and be mimicked by other endocrine and non-endocrine disorders. Establishing the correct diagnosis depends on accurate interpretation of thyroid function tests (TFTs), which is usually straightforward; however, in a minority of situations, the results of FT4, FT3 and TSH measurement either do not fit with the clinical picture and/or appear discordant with each other (so-called funny or weird TFTs) (Figure). In many such cases reassessment of the clinical context provides an explanation for the discrepant TFTS; in other instances, interference in one or other laboratory assays can be shown to account for divergent results; uncommonly, genetic defects in the hypothalamic-pituitary-thyroid axis are associated with anomalous TFTs. Failure to recognize these potential pitfalls can lead to misdiagnosis and inappropriate management.
30 Apr - 04 May 2011
European Society of Endocrinology