Thyroid Imaging, Uptake Scans, and Biopsy

A thyroid nodule is not an automatic biopsy. The first question is whether the thyroid is functioning normally, because a suppressed thyroid-stimulating hormone (TSH) changes the entire diagnostic pathway. For a newly discovered nodule, obtain serum TSH first. Diagnostic ultrasound of the thyroid and cervical lymph nodes follows to characterize the gland, measure each clinically relevant nodule, and identify suspicious lymph nodes. The TSH result then determines whether radionuclide imaging is useful. A low TSH suggests that one or more areas of thyroid tissue may be producing hormone autonomously. In that setting, a radionuclide scan comes before considering fine-needle aspiration (FNA). A normal or elevated TSH means radionuclide imaging does not help decide whether the nodule is malignant; ultrasound risk features and nodule size determine whether FNA is indicated. Do not order thyroid ultrasound simply because thyroid function tests are abnormal. In a patient with biochemical hypo- or hyperthyroidism but no palpable abnormality, goitre, neck asymmetry, or compressive symptom, ultrasound often finds incidental nodules that distract from the functional problem. A focused history and neck assessment establish urgency. Prompt specialist...