Thyroid nodule epidemiology and demographics

Worldwide, the incidence of thyroid nodule ranges from as low of 40,000 per 100,000 persons to a high of 71,000 per 100,000 persons with an average incidence of 50,000 per 100,000 persons. The incidence of thyroid cancer is estimated to be a total number of 48,288 cases annually in United states. Thyroid nodules are common, their prevalence being largely dependent on the identification method, as sensitivity and specificity of different methods for thyroid nodule diagnosis varies. In United States, the prevalence of thyroid nodule detected by palpation alone ranges from a low of 2,000 per 100,000 persons to a high of 6,000 per 100,000 persons, while the prevalence of thyroid nodule detected by ultrasound ranges from a low of 20,000 per 100,000 persons to a high of 35,000 per 100,000 persons. Worldwide, the prevalence of palpable thyroid nodule is approximately 5,000 per 100,000 in women and 1,000 per 100,000 in men living in iodine-sufficient parts of the world, and the prevalence of ultrasound detected thyroid nodules ranges from as low as 19,000 per 100,000 to as high as 68,000 per 100,000. Thyroid nodules commonly affects individuals younger than 20 and older than 50 years of age. Females are more commonly affected with thyroid nodules than males.

• Worldwide, the incidence of thyroid nodule ranges from as low of 40,000 per 100,000 persons to a high of 71,000 per 100,000 persons with an average incidence of 50,000 per 100,000 persons.^[1][2]
• The risk for malignancy in asymptomatic nodules found in non-irradiated glands is 0.45% to 13% (mean +/- SD = 3.9% +/- 4.1%), which means the incidence of malignant thyroid nodule ranges from as low as 250 per 100,000 persons to as high as 7000 per 100,000 persons approximately.^[1][2]
• The incidence of thyroid cancer is estimated to be a total number of 48,288 cases annually in United states.
• There is a large increase worldwide in the incidence of thyroid cancers. It is likely to be due to:^[1][2]

• • The use of head and neck external beam radiation, commonly used to treat benign childhood conditions between 1910 and 1960.
  • The increased detection of small papillary cancers secondary to more widespread use of neck ultrasound and fine-needle aspiration (FNA) of very small thyroid nodules.

Thyroid nodules are common, their prevalence being largely dependent on the identification method, as sensitivity and specificity of different methods for thyroid nodule diagnosis varies.^[3]

• In United States, the prevalence of thyroid nodule detected by palpation alone ranges from a low of 2,000 per 100,000 persons to a high of 6,000 per 100,000 persons, while the prevalence of thyroid nodule detected by ultrasound ranges from a low of 20,000 per 100,000 persons to a high of 35,000 per 100,000 persons.^[4]
• In United States, the prevalence of thyroid nodule detected by surgery or autopsy ranges from a low of 50,000 per 100,000 persons to a high of 65,000 per 100,000 persons, that correlate more with the prevalence detected by ultrasound.^[5]
• In the United States, 4 to 7 percent of the adult population have a palpable thyroid nodule.^[6][5]

Worldwide, the prevalence of palpable thyroid nodule is approximately 5,000 per 100,000 in women and 1,000 per 100,000 in men living in iodine-sufficient parts of the world, and the prevalence of ultrasound detected thyroid nodules ranges from as low as 19,000 per 100,000 to as high as 68,000 per 100,000. ^[5][6]

• There is a large increase worldwide in the incidence of thyroid cancers. The largest increase in thyroid cancer incidence has been observed in South Korea:^[7]

• • In 1993-1997, the incidence of thyroid cancer was estimated to be 12.2 cases per 100,000 individuals, while in 2003-2007, the incidence of thyroid cancer increased and was estimated to be 59.9 cases per 100,000 individuals.
  • Thyroid cancer is recognized as the most common cancer among women in South Korea.

• Thyroid nodules commonly affects individuals younger than 20 and older than 50 years of age.^[2]
• There is no association between the thyroid cancer development in a previous patient with the thyroid nodule and the age. ^[8][9]

• Females are more commonly affected with thyroid nodules than males.^[10]
• The female to male ratio is approximately 5 to 1.^[11]
• Males are more commonly affected with aggressive thyroid neoplasms and have a more fatality rate than women.^[12]
• Females are more commonly affected with follicular thyroid lesions than males.^[12]

• Although goiter is more prevalent in iodine deficient and developing countries, there are insufficient data regarding association of thyroid nodules and the country of residence.^[10][11]

Template:WH Template:WS