Thyroid malignancy markers on sonography are common in patients with benign thyroid disease and previous iodine deficiency.

Abstract

The purpose of this study was to evaluate the characteristics of benign thyroid nodules on sonography and ultrasound elastography in a population exposed to iodine deficiency. We conducted a prospective systematic evaluation of preoperative thyroid sonography and elastography in patients assigned for surgical excision of benign thyroid nodules. Two experienced sonographers performed all sonographic and elastographic examinations. Thyroid nodules were evaluated by 7 generally accepted sonographic malignancy risk markers and assigned an elasticity score on elastography. The final diagnosis of a benign thyroid nodule was based on histopathologic analysis of resected thyroid gland tissue. We evaluated 232 thyroid nodules in 105 patients (86 women and 19 men). In total, 57% of the examined nodules had 1 or 2 malignancy risk markers present, and 24% did not have any markers present. A solid nodule larger than 15 mm was the most common malignancy risk marker observed (63%), followed by low elasticity (33%), microcalcifications (26%), and hypoechogenicity (15%). In an analysis stratified according to the number of nodules (solitary versus multiple), low elasticity was described more frequently in solitary nodules (61.9% versus 30.4%; P= .004). A large nodular volume was a predictor (P < .05) of microcalcifications and intranodular vascularization, whereas an absent halo sign and a solid nodule were found less frequently in nodules with larger volumes. Our results show that routine preoperative malignancy risk evaluation of presumably benign thyroid nodules is of little value when performed on patients exposed to iodine deficiency.