Non-palpable thyroid nodules in a borderline iodine-sufficient area: Detection by ultrasonography and follow-up

Thyroid ultrasonography was performed in 482 subjects, free of known thyroid disease and living in a borderline iodine-sufficient urban area, to assess the prevalence of non-palpable thyroid nodules and evaluation their evolute during a 3-yr follow-up. The mean (±SD) thyroid volume in the whole study group was 10.9±3.7 ml and was higher in males (12.9±3.6 ml) than in females (9.2±2.9 ml) (p2=10.21; p=0.001). Multiple nodules were found in 3/464 subjects (0.6%) with a thyroid of normal volume and in 3/18 (16.6%) subjects with goiter (x²=24.31; p35 yr than in those 2=7.47; p=0.0062). A significant increase (>30%) of nodular volume was found in 5 subjects, while an increased number of nodules was found in 8. In conclusion, thyroid ultrasonography reveals the presence of thyroid nodules in a significant proportion of apparently thyroid disease-free subjects living in a borderline iodine-sufficient urban area. Incidentally discovered thyroid nodules are associated with goiter and are likely to progress in volume and number.