Sonography of thyroid nodules with peripheral calcifications

This study was designed to assess the role of sonography (US) in the differentiation of benign from malignant thyroid nodules with peripheral calcifications.

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.

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.

Interruption and thickening of peripheral calcifications and decreased internal echogenicity of a thyroid nodule with peripheral calcifications are in favor of malignancy.