The value of calcification in CT differentiating benign and malignant thyroid lesions / 中华放射学杂志

ABSTRACT

Objective To study the diagnostic value of calcification in differentiating benign and malignant thyroid lesions. Methods CT images of 318 consecutive patients with pathologically proven thyroid lesions were retrospectively reviewed by two radiologists. The following characteristics of calcification on CT images were evaluated (1) size (≤2 mm indicating microcalcification and > 2 mm or shelly and irregular shape indicating macrocalcification, and both features indicating mixed calcification), (2) number (single or multiple) and (3)location (internal or edge). χ~2 test was used for statistical analysis. Results Oft he 318 cases, 48 were diagnosed as malignant (papillary carcinoma 26, follicular carcinoma 7, medullary carcinoma 3 and microcarcinoma 12) and 270 were benign (nodular goiter 36, adenoma 170, nodular goiter with adenoma 38 and adenoma with Hashimoto's thyroiditis 26). Calcification was found in 60 cases (18.9%). Among them 21 (papillary carcinoma 12,microcarcinoma 6,follicular carcinoma 2 and medullary carcinoma 1) were malignant(43.8%) and 39(nodular goiter 6, adenoma 13,nodular goiter with adenoma 19 and adenoma with Hashimoto's thyroiditis 1) were benign (14.4%) (P < 0.01). Sensitivity and specificity for diagnosing thyroid carcinoma were 43.8% (21/48) and 85.6% (231/270), respectively. Microcalcification was found in 37 cases (malignant 8, benign 29) and macrocalcification was found in 23 cases(malignant 13, benign 10) (P < 0.01) . Sensitivity and specificity of macrecalcification for diagnosing thyroid carcinoma were 61.9% (13/21) and 74.4% (29/39), respectively. Single calcification was found in 31 cases (malignant 13, benign 18) and multiple calcification was found in 29 cases(malignant 8, benign 21) (P >0.05). Internal calcification was found in 15 cases of malignant lesions(71.4%) and 12 of benign lesions(30.8%); Edge calcification was found in 6 cases of malignant and 27 of benign, (P <0.01). Sensitivity and specificity of internal calcification for diagnosing thyroid carcinoma were 71.4% (15/21) and 69.2% (27/39), respectively. Conclusion Internal calcification or(and) macrocalcification of the thyroid lesions may strongly suspect thyroid carcinoma and fine-needle aspiration or surgery should be further performed.