肝様腺癌―臨床の立場から

Clinical Features of Hepatoid Adenocarcinoma

要旨　当院で外科切除され，組織学的に肝様腺癌と診断された36例36病変の臨床病理学的特徴を検討した．約90％が進行癌で，2型病変が最多であった．内視鏡像は潰瘍辺縁がシャープで周堤隆起が非腫瘍に覆われる病変が多く，易出血性で潰瘍底に凝血塊が付着する病変も認められた．病理組織学的には全病変の癌浸潤部において肝様構造を有していた．進行癌に限ると，静脈侵襲のみが通常型胃癌と比べ有意に高かった．同時性と異時性肝転移は約20％と約40％で，合わせて約60％であった．胃癌死した症例は55.6％（生存期間中央値10か月）と予後不良であった．ただし，肝転移を認めなかった症例では69.2％が5年以上生存していた．

　Hepatoid adenocarcinoma is one of the AFP-producing gastric cancers. We evaluated the clinicopathological features of 36 gastric cancers with hepatoid adenocarcinoma in 36 patients surgically resected at our hospital. Thirty-three（91.7％）lesions were advanced cancers and type 2 lesions were found most frequently with sharp-edged ulceration and surrounding elevation covered with non-neoplastic mucosa. Histologically, the component of hepatoid adenocarcinoma was found only in the invasive part of the tumor. Advanced lesions of hepatoid adenocarcinoma had significantly higher possibility of vascular invasion compared to the common type of advanced gastric cancer. The rates of synchronous and metachronous liver metastases were about 20％ and 40％, respectively. Of all patients, 20（55.6％）died from those diseases and the median survival periods were only around 10 months. In contrast, of 13 patients without any liver metastases, 9（69.2％）were survived for more than 5 years. The results of this study indicate that appropriate diagnostic strategy and treatment modality for hepatoid adenocarcinoma is desirable because this tumor has a high potential for liver metastasis and the prognosis of these patients is very poor.