CTにて長期経過を追えたsmall duct typeの肝内胆管癌の3例

Three cases of small duct type of intrahepatic cholangiocarcinoma showing slow growth：comparison with current and initial CT images

2019年に改訂された消化器腫瘍WHO分類第5版において肝内胆管癌はsmall duct carcinoma（SDC）とlarge duct carcinoma（LDC）の2つに分類された^1）。従来，混合型肝癌の亜型とされていた細胆管癌（cholangiolocellular carcinoma：CoCC）はSDCの一亜型として分類されるようになった。今回我々は外科切除材料にてSDCと診断された症例で，後方視的にその初期像がCTで確認し得た3例を経験した。SDCの自然経過を知るうえで貴重な症例と考え，報告する。

In the 2019 digestive system tumours WHO classification, intrahepatic cholangiocarcinoma was classified into small duct carcinoma（SDC）and large duct carcinoma（LDC）. LDC may evolve from biliary intrahepatic neoplasm and intrahepatic papillary neoplasm of the bile duct, but the initial lesion of SDC is unknown. In addition, it is suggested that SDC shows slow growth, and its prognosis is better than that of LDC；however sufficient studies have not yet been conducted on this classification. We experienced three cases of SDC, which were retrospectively followed for a long term. We consider these cases valuable for understanding the natural course of SDC.