Purpose: This study was designed to assess the role of sonography (US) in the differentiation of benign from malignant thyroid nodules with peripheral calcifications.
Methods: Sixty-four thyroid nodules with peripheral calcifications that were detected on US were included in the study. Nineteen nodules (30%) were benign, and 45 nodules (70%) were malignant. We retrospectively compared the US findings of the benign and malignant nodules, including interruption, thickening (>or=0.5 mm and over more than 50% of the circumference) of calcifications, internal echogenicity, margin, and presence of cystic change, size, and shape. Univariate and multivariate logistic regression analyses were performed.
Results: Interruption of peripheral calcifications was more common in malignant nodules (84%) than in benign nodules (53%) (OR, 7.9; 95% CI, 1.3-48.4; p < 0.05). Thickening of the peripheral calcification was seen more frequently in malignant nodules (64%) than in benign nodules (11%) (OR, 14.7; 95% CI, 1.8-117.5; p < 0.05). For internal echogenicity, malignant nodules (58%) were more often hypoechoic than benign nodules (OR, 23.6; 95% CI, 2.2-256.3; p < 0.01). The mean tumor size was 1.1 cm for malignant nodules and 1.2 cm for benign nodules (p > 0.05). There were no significant differences for the presence or absence of cystic change, size, shape, and margin between malignant and benign nodules.
Conclusion: Interruption and thickening of peripheral calcifications and decreased internal echogenicity of a thyroid nodule with peripheral calcifications are in favor of malignancy.