How shall we manage the incidentally found thyroid nodule?

Thyroid incidentalomas are commonly found on cross-sectional imaging of the neck and they are equally likely to be malignant as palpable thyroid nodules. Guidelines on their management are conflicting. Ultrasonography cannot accurately differentiate benign from malignant thyroid nodules and fine needle aspiration biopsy should be used selectively to avoid over-diagnosis and over-treatment. If the clinician follows current guidelines for the investigation of thyroid incidentalomas a proportion of malignant incidentalomas will inevitably be missed.Whether this is clinically important is controversial as it is generally agreed that the natural history of small incidental thyroid cancers is indolent. However a subset may have a more aggressive behaviour and it is not currently possible to predict whether a malignant incidentaloma will progress to clinical disease or remain latent. In this article we review the evidence-base around the current guidelines for investigating thyroid incidentalomas and suggest a practical approach to their management.