池田 弘¹, 川野 示真子¹, 横井 徹¹, 石崎 正彦¹, 藤井 守¹, 小西 明美¹, 井上 武紀¹, 仁科 恭一郎¹, 藤井 正子², 小林 伊津美², 文屋 千恵子², 石坂 克己², 平田 和文³

Hiroshi IKEDA¹, Shimako KAWANO¹, Toru YOKOI¹, Masahiko ISHIZAKI¹, Mamoru FUJII¹, Akemi KONISHI¹, Takemichi INOUE¹, Kyouichirou NISHINA¹, Masako FUJII², Izumi KOBAYASHI², Chieko BUNYA², Katsumi ISHIZAKA², Kazuhumi HIRATA³

¹倉敷中央病院内科, ²倉敷中央病院超音波室, ³平田内科医院

¹Department of Internal Medicine, Kurashiki Central Hospital, ²Laboratory of Ultrasonography, Kurashiki Central Hospital, ³Hirata Clinic

キーワード : Small liver cancer, Hyperechoic HCC, US-guided needle biopsy

In order to clarify the ultrasonographic and clinical features of a small hepatocellular carcinoma (HCC), 22 small HCC were examined retrospectively. The ratio of short/long in terms of the length of a tumor≥0.8 was observed in 86% of cases. However, other findings were rarely detected: marginal hypoechoic zone (18%), lateral shadow (0%), posterior echo enhancement (23%). This tendency was obvious in small HCC less than 1 cm in diameter. In contrast, the appearance of a low echoic area was often seen in hyperechoic HCC, which represents adenomatous hyperplasia (AH) or well differentiated HCC. The sensitivity of the angiography and computed tomography was 100% in a hypoechoic HCC measuring 1 to 2 cm. In contrast, most of hyperechoic HCC were angiographically undetected HCC. Therefore, a US-guided needle biopsy was useful for final diagnosis. Moreover, the growth of hyperechoic HCC was slower than that of hypoechoic HCC. Histologically, some cases of hyperechoic HCC were closely related to AH. These results suggest that the atypical clinical findings of hyperechoic HCC are due to its unique histological features.