Ultrasonographic screening for occult thyroid cancer

It has been shown that occult thyroid carcinoma can be identified in about 10% of thyroid glands in autopsy. The purpose of this study was to evaluate the prevalence of asymptomatic thyroid carcinoma in the Hong Kong Chinese population by ultrasonographic screening.

Volunteer subjects without symptoms of thyroid disease were recruited for ultrasonographic screening for thyroid cancer. A total of 1140 subjects were recruited in this study.

Thyroid nodules were found in 45% subjects (511 of 1140); the mean age was 48 years. Ultrasonographic-guided aspiration cytology was performed in 258 subjects. Twenty-six subjects (2.3%) had cytologic findings suspicious of malignancy. Fourteen subjects (1.2%) had pathologic diagnosis of thyroid cancer, including 13 papillary carcinomas and 1 follicular carcinoma.

A high incidence of occult thyroid cancer could be identified on ultrasonographic screening. Subjects could benefit with early diagnosis with either early intervention or close monitoring.