Increasing thyroid cancer incidence is due to the increased detection of small papillary cancers and may not interpreted as an increase in the true occurrence of disease. Further workup of thyroid incidentalomas—impalpable nodules detected fortuitously during a radiological investigation—may contribution of the increasing thyroid cancer. Screening asymptomatic adults or children for thyroid cancer using either neck palpation or ultrasonography is not recommended in the US Preventive Services Task Force and the Korean lifetime health maintenance program. Generally, only thyroid incidentalomas > 1 cm should be evaluated, since they have a greater potential to be clinically significant cancers and thyroid nodules < 1 cm that require evaluation because of suspicious US findings, associated lymphadenopathy, a history of head and neck irradiation, or a history of thyroid cancer in one or more first-degree relatives
