山本 貴嗣¹, 竹内 和男¹, 長島 夏子¹, 本庶 元¹, 桜井 則男¹, 奥田 近夫¹, 松田 正道², 橋本 雅司², 渡邊 五朗², 関 邦彦³

Takatsugu YAMAMOTO¹, Kazuo TAKEUCHI¹, Natsuko NAGASHIMA¹, Hajime HONJO¹, Norio SAKURAI¹, Chikao OKUDA¹, Masamichi MATSUDA², Masashi HASHIMOTO², Goro WATANABE², Kunihiko SEKI³

¹虎の門病院消化器科, ²虎の門病院消化器外科, ³虎の門病院病理部

¹Department of Gastroenterology, Toranomon Hospital, ²Department of Surgery, Toranomon Hospital, ³Division of Pathology, Toranomon Hospital

キーワード : Hepatocellular carcinoma, Hyperechoic liver tumor, Lipomatous tumor, Ultrasonography

We report two cases of relatively large hepatocellular carcinomas (HCC) with marked fatty metamorphosis, which were difficult to differentiate from lipomatous tumors (LT). Both tumors occurred in the normal livers, and both were vigorously hyperechoic and had posterior acoustic shadows on ultrasonography (US). Because computed tomography, magnetic resonance imaging, and other imaging modalities were incapable of differentiating HCC from LT, the diagnosis had to be based on histologic examination. On retrospective observation of US imaging, however, those tumors were found to have presented evidence specific for HCC; this included, for example, halo or nodule in nodule, which may lead to an accurate preoperative diagnosis. A survey of the literature suggested that such findings were rare in LT. Such US findings as halo and nodule in nodule were thus considered useful in the differential diagnosis of HCC and LT in cases of large hyperechoic liver tumors, and careful observation of US imaging may be important.