2011 Volume 25 Issue 5 Pages 789-797
Objective: Since thyroid nodules are frequently found in Ningen Dock, a clinical guideline with lines of evidence is required to conduct efficient screening for those that should be treated. In this study, we analyzed the results of ultrasonographic examinations and the changes in their findings.
Methods: We carried out thyroid ultrasonography for all 21,856 people who underwent Ningen Dock from April, 2004 to March, 2009.
Results: Thyroid nodules were detected in 4,978 subjects (22.8%). Cytological diagnoses were as follows: class I or II (Group B) in 165 subjects, class III (Group B/M) in 20, and class IV or V (Group M) in 57. Between groups, there were no significant differences in percentages of each sex, age or nodule diameter. Changes in the nodule diameter were +0.2±0.3, +0.8±0.5, and +1.3±0.5 mm/year in Group B, B/M and M, respectively. The nodule diameter in Group M increased significantly faster than that in Group B. In Group M, there were no subjects with a decrease in nodule diameter of more than 1.0 mm/year M. Also, although all malignant nodules of 11 mm or more in diameter in this group grew by more than 1.0 mm/year, most malignant nodules of 10 mm or less in size exhibited no change in diameter.
Conclusions: The findings of this study suggest that it is important to make decisions on what to do about the thyroid nodules frequently found in ultrasonographic screening based on nodule diameter and subsequent observations.
