粘液性嚢胞性新生物を模倣した肝細胞癌の嚢胞性変性

Cystic Degeneration of Hepatocellular Carcinoma Mimicking Mucinous Cystic Neoplasm.

• Jangwon Lee
• Namhee Lee
• Hye Kyoung Yoon
• Yeon Jae Lee
• Sung Jae Park

抄録

肝細胞癌（HCC）では、腫瘍の自然退縮は極めて稀な事象であり、利用可能な報告はわずかである。臨床情報の蓄積と腫瘍免疫遺伝学の進歩により，動脈血栓症，炎症，腫瘍の急速な増殖など，HCCの嚢胞性変化のいくつかの機序が示唆されてきた。本論文では、異常な放射線学的所見のため、当初は肝臓の粘液性嚢胞性新生物と誤診されていたHCCが部分的に退縮した珍しい症例を報告する。B型肝炎ウイルスと肝硬変を合併した78歳女性が、約5cmの大きさの肝嚢胞性腫瘤を呈した。嚢胞壁から内側に向かって乳頭状に突出していることから、最初の印象は肝臓の粘液性嚢胞性新生物であった。この患者は外科的切除を受け、最終的に約80％の壊死を認めたHCCの嚢胞性変性症であった。この症例は、肝胆道画像検査でHCCのリスクが高い患者に肝嚢胞性新生物が現れた場合、鑑別診断でHCCの嚢胞性変性を考慮することが賢明であることを示唆している。

Spontaneous regression of tumors is an extremely rare event in hepatocellular carcinoma (HCC) with only a few reports available. With the accumulation of clinical information and tumor immunogenetics, several mechanisms for the cystic changes of HCC have been suggested, including arterial thrombosis, inflammation, and rapid tumor growth. This paper reports an uncommon case of the partial regression of HCC, which was initially misdiagnosed as a mucinous cystic neoplasm of the liver due to the unusual radiologic findings. A 78-year-old female with the hepatitis B virus and liver cirrhosis presented with an approximately 5 cm-sized cystic mass of the liver. From the radiologic evidence of a papillary-like projection from the cyst wall toward the inner side, the initial impression was a mucinous cystic neoplasm of the liver. The patient underwent a surgical resection and finally, cystic degeneration of HCC, in which approximately 80% necrosis was noted. This case suggests that if a cystic neoplasm of liver appears in a patient with a high risk of HCC on a hepatobiliary imaging study, it is prudent to consider the cystic degeneration of HCC in a differential diagnosis.