Papillary carcinoma of the thyroid

The clinical behavior and mortality rate of papillary carcinoma of the thyroid varies widely, and clinically insignificant microscopic foci of the disease are frequently found. Dietary iodine and radiation to the head and neck in childhood play a role in etiology. Needle aspiration cytology provides a highly accurate diagnosis. Ultrasound, radioactive iodine, and technetium scans are not specific and should only be used to complete diagnostic studies when aspiration cytology is negative for papillary carcinoma. The most important aspect of prognosis of an individual patient with papillary carcinoma of the thyroid is the age at which the disease is diagnosed, with an excellent prognosis, even in advanced primary disease or extensive lymph node involvement, in children and young adults. A multifactorial clinical risk group definition (AMES) is easy to use and reliably separates patients into low risk and high risk. Since 90% of patients with this disease rarely have metastases or late complications from the cancer, total or subtotal thyroidectomy is necessary in only 10% of cases for later use of postoperative radioactive iodine. More conservative surgical procedures are advised in low-risk patients. Papillary carcinoma incidentally found during operation for other conditions such as Graves disease or thyroiditis and reported first on the permanent pathology reports are always clinically insignificant and completely cured by removal; total thyroidectomy should be completely avoided. Postoperatively, thyroid hormone supplementation may be unnecessary after relatively conservative surgery in selected low-risk patients. Thyroid hormone must be maintained permanently after total or subtotal thyroidectomy.