Metastases to the thyroid gland: how does this affect cytohistological diagnoses?

Metastases to the thyroid gland can present a diagnostic challenge with respect to the cytological and histological evaluation of thyroid lesions. Data from the literature indicates that the rate of metastases to the thyroid gland ranges between 0% and 24% for patients with thyroid nodules in autopsy series, but according to clinical series the reported incidence varies between 0·1% and 3%.1–5 This discrepancy shows that metastatic thyroid lesions are frequently missed or misdiagnosed in their clinical evaluation.