Thyoid calcifications patterns in sonography and its association with thyroid carcinoma

Objective To evaluate the significance of sonographically detected thyroid calcification in the diagnosis of thyroid carcinoma.Methods Five hundred and twenty-two patients with thyroid disease,including 119 with thyroid cancer,were included in the study.Each patient underwent preoperative,highresolution sonography to evaluate the thyroid gland for the presence of calcification.Calcifications were classified:type Ⅰ,microcalcification;type Ⅱ,coarse calcification;type Ⅲ,annular or"egg-shell"calcification;typeⅣ,calcified nodules within a cyst.Results The incidence of calcification and microcalcification was significantly higher in thyroid cancer than in benign nodules(P＜0.001).The appearance of microcalcifications was highly specific for malignancy with a sonographic specificity of 88%.The sensitivity was 60%,and the odds ratio(0R)was 11.28.The incidence of calcifications of type Ⅱ and type Ⅲ did not differ significantly between the benign and malignant groups.Calcifications of type Ⅳ were showed totally in benign groups.Patients younger than 45 years with calcified nodules constituted a highrisk group,with a OR of 11.33 versus 2.96 in patients older than 45 years with calcified nodules.In the group of solitary thyroid nodules,the incidence of cancer in the calcified nodules was higher than in the nodules without calcifications,with a OR of 20.48.Conclusions The detection of thyroid calcifications by sonography is diagnostically valuable,especially in eases involving a solitary nodule or a young person.The presence of calcifications in these cases should raise the suspicion of malignancy,especially microcalcification. Key words: Ultrasonography; Thyroid neoplasms; Calcinosis