肝細胞癌と鑑別に苦慮した肝血管筋脂肪腫の1例

A case of hepatic angiomyolipoma that was difficult to differentiate from hepatocellular carcinoma

肝血管筋脂肪腫（hepatic angiomyolipoma：HAML）は1976年に初めて報告されたまれな間葉系腫瘍である^1）。HAMLは，脂肪，平滑筋，血管の3成分の構成比率によって様々な画像所見を示す。今回我々は，腹部超音波検査で偶発的に発見された肝腫瘤に対する精査目的のCT，MRIにおいて古典的肝細胞癌と鑑別が困難であったHAMLの1例を経験したため，これを報告する。

Hepatic angiomyolipoma is a rare mesenchymal tumor, first reported in 1976, that shows diverse imaging findings depending on the compositional ratio of fat, smooth muscle and blood vessels. Here, we report a case of a hepatic mass detected on abdominal ultrasonography that was difficult to differentiate from classic hepatocellular carcinoma based on CT, MRI or FDG-PET evaluations. When a liver mass demonstrates early enhancement and subsequent washout, hepatocellular carcinoma is usually considered. However, in the absence of risk factors and with no elevation of tumor markers, hepatic angiomyolipoma should also be included in the differential diagnosis.