前立腺肉腫の胃壁内転移の1例

Gastric Metastasis of Prostate Sarcoma, Report of a Case

要旨●患者は60歳代，男性．前立腺腫大のスクリーニング目的でEGD（esophagogastroduodenoscopy）を施行し，胃角前壁大彎に0-IIa型病変を認めたため，ESD（endoscopic submucosal dissection）の方針となった．EGDから2か月後，ESD時の観察で胃体中部大彎後壁に，前回認めなかった白色調の隆起性病変を認めた．NBI（narrow band imaging）拡大像では，隆起表面は概ね無構造で，belagが付着していた．低分化型の粘膜内癌と診断し，ESDを施行した．同病変の病理組織学的診断は，免疫組織化学染色などから肉腫となったが，前立腺腫瘍の組織生検からも本病変と同じ肉腫の組織が認められた．本病変の発見以前に前立腺肉腫が存在したこと，病変が2か月で出現したことから，臨床的に前立腺肉腫の胃転移と診断した．本症例は胃転移性肉腫の内視鏡像を詳細に観察したものであり，今後の内視鏡診断をするうえで貴重な症例であった．

　A 60s man with a slightly elevated type 0-IIa gastric cancer lesion of the anterior wall of the gastric angle underwent screening for prostate enlargement and ESD（endoscopic submucosal dissection）2 months after the screening. When we performed ESD, a white-toned elevated lesion on the great curvature of the gastric body was revealed, which was not previously observed. Magnifying endoscopy with narrow band imaging revealed that the surface structure was almost unstructured, and the glandular duct structure remained although it was rough. ESD was performed on the lesion for diagnosis and treatment. On pathological examination, the tumor was diagnosed as sarcoma. Histological biopsy of the prostate tumor revealed the same sarcoma findings as the gastric tumor. Because the prostate tumor was present before the discovery of the gastric tumor and the lesion appeared 2 months later, it was clinically diagnosed as gastric metastasis of prostate sarcoma.