Differentiation of thyroid nodules with macrocalcifications: role of suspicious sonographic findings.
OBJECTIVE
The purpose of this study was to determine which types of macrocalcifications are associated with thyroid carcinoma and to assess the role of other suspicious sonographic findings in thyroid nodules with macrocalcifications.


METHODS
Our Institutional Review Board approved this retrospective study, and informed consent was not required. We reviewed sonographic findings of thyroid nodules in 722 patients that underwent thyroid surgery in our institution between March 2006 and August 2006. Sonographic results were grouped into 3 types of macrocalcifications. Each lesion was evaluated on the basis of other suspicious sonographic criteria, including marked hypoechogenicity, irregular or microlobulated margins, and a taller-than-wide shape. Sensitivity and specificity based on sonographic criteria were calculated and compared among the subtypes of macrocalcifications.


RESULTS
One hundred seventy-four nodules showed macrocalcifications; 116 were malignant, and 58 were benign. Among the macrocalcification categories, solitary calcifications were more common in benign thyroid lesions, whereas coarse calcifications not otherwise specified were more common in malignant lesions (P < .05). Although the risk of malignancy was 17.2% in cases with no suspicious sonographic findings, the risk of malignancy was up to 82.8% in cases with at least 1 of the sonographic criteria (P < .05). On the basis of the suspicious sonographic criteria, the overall sensitivity was 82.8%. There was no statistically significant difference in sensitivity among the macrocalcification subtypes (P > .05).


CONCLUSIONS
Suspicious sonographic features such as marked hypoechogenicity, irregular or microlobulated margins, and a taller-than-wide shape can play important roles in differentiating benign and malignant thyroid nodules with macrocalcifications.
Kim
Min Jung
MJ
Department of Radiology, Research Institute of Radiological Science, Yonsei University Heath System, 134 Shinchon-dong, Seodaemun-ku, Seoul 120-752, Korea.
Kim
Eun-Kyung
EK
Kwak
Jin Young
JY
Park
Cheong Soo
CS
Chung
Woong Youn
WY
Nam
Kee-Hyun
KH
Youk
Ji Hyun
JH
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002114:Calcinosis / Q000000981:diagnostic imaging*; D002648:Child; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D016606:Thyroid Nodule / Q000000981:diagnostic imaging*; D014463:Ultrasonography