HCG高値を示し，絨毛上皮腫様変化を伴った男性残胃癌の1剖検例

Adenocarcinoma with Chorionepitheliomatous Change in the Remnant Stomach of a Male Adult, Report of a Case

　最近，異所性絨毛上皮腫やHCGなど各種のホルモン産生を示す癌について注目されるようになり，その発生およびホルモン産生機転には種々の見解が示されているが，なお未解決の問題が多い．今回われわれは，絨毛上皮腫様変化を伴った男性の残胃癌剖検例を経験したので報告する．

　A 75 year-old man was admitted because of epigastric pain. In the past history, the patient had gastrectomy for early gastric cancer two years and four months before. Histological examination of this cancer was not performed.

　On physical examination gynecomastia with tenderness was found. Liver scan revealed a large defect in the right lobe of the liver. Upper G-Ⅰ series and endoscopic examination suggested a Borrmann type 1 gastric cancer. The histological finding of gastric biopsy specimen revealed poorly differentiated adenocarcinoma.

　Patient died of general weakness three weeks after admission.

　At autopsy there was a Borrmann type 1 tumor (4.4×2.5 cm) on the lesser curvature of the remnant stomach. Multiple metastatic lesions with hemorrhage were seen in the liver and lungs. Histological study showed that gastric tumor was composed of adenocarcinoma and chorionepithelioma. The final diagnosis of adenocarcinoma with chorionepitheliomatous change in the stomach was done because of remarkably high level of serum HCG in the blood at autopsy.

　There are several opinions as to the histogenesis of primary chorionepithelioma in the stomach. We suggest the retrodifferentiation of carcinoma cells because of the coexistence of adenocarcinoma and chorionepithelioma with transitional area in between.