Thyroid cancer

Thyroid cancer most commonly presents as an asymptomatic thyroid nodule detected by palpation or ultrasound in women in their 30s or 40s.

The most important diagnostic test is fine-needle aspiration.

Treatment of differentiated (papillary, follicular, oncocytic [Hürthle cell]) thyroid cancer depends on pre-treatment assessment of risk and usually includes total thyroidectomy or lobectomy. Risk assessment (based on surgical and pathological findings) and assessment of disease status determines if radioactive iodine therapy, thyroid-stimulating hormone (TSH) suppression, or both should be used.

Treatment differs for uncommon types of thyroid cancer (such as anaplastic, medullary, or primary thyroid lymphoma), and should be tailored accordingly.

Prognosis depends on risk-group stratification.

Thyroid cancer encompasses a spectrum of pathological variants that are heterogeneous in clinical behaviour.

The main histopathogical types are: differentiated thyroid carcinoma (including papillary, follicular, oncocytic [previously known as Hürthle cell]); medullary thyroid carcinoma; and undifferentiated (anaplastic) thyroid carcinoma.

Differentiated thyroid carcinoma is most common (>90% of cases; papillary carcinoma accounts for around 80% of cases) and generally has an indolent disease course.[1]Haugen BR, Alexander EK, Bible KC, et al; American Thyroid Association Guidelines Task Force on Thyroid Nodules and Differentiated Thyroid Cancer. 2015 American Thyroid Association management guidelines for adult patients with thyroid nodules and differentiated thyroid cancer. Thyroid. 2016 Jan;26(1):1-133. https://www.liebertpub.com/doi/10.1089/thy.2015.0020 http://www.ncbi.nlm.nih.gov/pubmed/26462967?tool=bestpractice.com ​ Anaplastic thyroid carcinoma is extremely aggressive.