植野 映¹, 伊東 紘一², 斉藤 建³, 若杉 尋¹, 森岡 恭彦¹

Ei UENO¹, Kouichi ITOH², Ken SAITO³, Hiro WAKASUGI¹, Yasuhiko MORIOKA¹

¹自治医科大学外科学教室, ²自治医科大学臨床病理学教室, ³自治医科大学病理学教室

¹Department of Surgery, Jichi Medical School, ²Department of Clinical Pathology, Jichi Medical School, ³Department of Pathology, Jichi Medical School

キーワード : breast, ultrasound, breast cancer, diagnosis, ultrasonic tissue characterization

Ultrasonographic examination had been performed in 46 patients with breast cancer and in 366 patients with the other breast diseases. Among these patients, ultrasound mammographic patterns and histological appearances were compared in 152 patients, whose diagnosis had been established on the biopsy specimens. This comparative study led us to conclude;
(1) Halo in echogram may be produced by increased collagen fibers and by irregular tumor invasion to the surrounding tissues.
(2) Heterogeneous internal echoes are correlated to irregular structure of collagen fibers, calcification and necrotic tissues.
(3) Tadpole-tail sign, lateral shadow sign and acoustic middle shadow sign are explained by refraction and attenuation of the ultrasound in the tumor tissue.
The accuracy rate of the diagnosis was 89.1%. Fibroadenoma with increased collagen fibers often showed a halo and an acoustic middle shadow sign, which sometimes misguided us to a false positive reading for breast cancer. The echographic patterns may be varied mainly by the amount and distribution of the collagen fibers and liquid in the breast tissues. Further investigations on the ultrasonic tissue characterization are necessary for the accurate echographic diagnosis of the breast diseases.