Thyroid Nodules and Bethesda Cytology

Thyroid nodules are common, but most are benign. The clinical task is not to find every microscopic papillary carcinoma; it is to identify the smaller group of lesions with clinically meaningful malignant potential while avoiding unnecessary biopsy, surgery, and lifelong treatment. The rise in thyroid cancer incidence in Canada alongside relatively stable mortality is consistent with increased detection of small, indolent papillary cancers. For that reason, screening asymptomatic people for thyroid cancer is not recommended. A nodule found incidentally still deserves a risk-based assessment, but its discovery does not automatically justify FNA or surgery. Papillary and follicular tumours arise from follicular cells. Papillary carcinoma more often spreads through cervical lymphatics, whereas follicular carcinoma more often spreads through the bloodstream. That distinction explains why a suspicious cervical node particularly raises concern for papillary disease, while a follicular-patterned aspirate still requires surgical assessment of the capsule and blood vessels. Medullary thyroid carcinoma arises from parafollicular C cells and changes the clinical pathway. A family history of medullary thyroid carcinoma or a thyroid cancer syndrome is therefore not simply another risk factor; it...