張 裕泰, 飯田 太

Yutai CHANG, Futoshi IIDA

信州大学医学部第2外科

Department of Surgery, Shinshu University School of Medicine

キーワード : Microcarcinoma of Thyroid, Ultrasonogram, Pathology of Thyroid

Twenty-nine thyroid nodules under 10 mm in diameter detected by ultrasonography in 26 patients were examined in this study. These nodules were operated on after being diagnosed as microcarcinoma and the patients were followed-up with ultrasonograms for more than one year. Ultrasonographic patterns of the nodules were classified into three types: Type I included masses with a high echogenic dot and an acoustic shadow, Type IIa included masses with high echogenic dots surrounded by low level echoes and sharply defined boundaries Type IIb included masses with an acoustic shadow and the same echogenic dots as Type IIa, and Type III included high echogenic dots surrounded by low level echoes with irregular borders.
Carcinoma was found in 33.3% of Type I, 50% of Type II, and 69.2% of Type III subjects.
The histologic classifications of microcarcinoma were 13 papillary and 2 medullary carcinomas. The ultrasonographic features were analyzed, comparing them with histologic findings of the nodules, and were then evaluated from the view point of microcarcinoma diagnosis.