1Department of Surgery, Toranomon Hospital, 2Okinaka Memorial Institute for Medical Research
Halo, Character of halo, Irregular halo, Histological capsular invasion
Ultrasonographic patterns of thyroid nodules were correlated with pathologic findings. Thyroid nodules were examined with a real-time ultrasound scanner (HITACHI EUB-40,5 MHz convex type probe) equipped with a jelly pack produced on a centrifuge. On thyroid ultrasonography, the halo sign appeared in cases of follicular-pattern-dominant tumor. Histological capsular invasion appeared in seven of the ten cases presenting irregular halo. In diagnosing histological capsular invasion, sensitivity was 88%, specificity was 67%, and accuracy was 76%. Chai-square evaluation indicated that this finding was statistically significant (p<0.05). Thyroid nodules with irregular halo signs are carcinomas with capsular invasion. The authors are now diagnosing thyroid nodules with irregular halo signs as follicular-pattern-dominant carcinomas, though more ultrasonographic case studies will be necessary before the diagnoses of histological type.