Thyroid Cancer in Thyroid Nodules Diagnosed Using Ultrasonography and Fine Needle Aspiration Cytology

Ultrasound and fine needle aspiration cytology are advocated as first-line examinations for the assessment of thyroid nodules. This review investigates the incidence of thyroid cancer in thyroid nodules after ultrasonographic examination. Furthermore, patient characteristics, histological patterns, and therapeutic results among patients who received thyroid ultrasound and fine needle aspiration cytology are discussed. The incidence of thyroid cancer in thyroid nodules, as detected by thyroid ultrasound, was found to range from 7.9% to 32.7% depending on the selected population. The incidence of thyroid cancer in thyroid nodules reported depends on the studied cohort, ethnic group, age, sex and iodine intake. Radiation exposure is also an important factor. Of the 6,330 patients with thyroid nodules who underwent surgical treatment, benign lesions were observed in 75.5% (4,782 cases) of the cases. Papillary thyroid carcinoma was observed in 79.8% (1,236 cases) of the 1,548 malignant cases. The percentage of malignancy was found to increase after the age of 50 in both men and women. A decrease in tumor size correlated with decreased cancer mortality; however, the beneficial effects of a small tumor size were not seen in older patients. Radiation-exposed populations and thyroid nodules or thyroid cancer were major problems from the atomic bomb in World War II and the Chernobyl nuclear accident. However, most occupational radiation exposure studies have not illustrated this harmful effect of radiation. In summary, over the time course in the diagnosis of thyroid cancer in nodules, there is a trend of decrease in tumor size and increase in the patient's age. The diagnosis and treatment of non-well-differentiated thyroid cancer in ageing patients is a major obstacle that needs to be overcome in the future.