NBI併用拡大観察が有用であった虫垂印環細胞癌の1例

Signet-ring Cell Carcinoma of the Appendix Observed Using Magnifying Endoscopy with Narrow Band Imaging, Report of a Case

要旨●患者は40歳代，女性．近医にてスクリーニング目的で施行された下部消化管内視鏡検査（TCS）で盲腸に異常を認め，生検の結果虫垂癌が疑われ当院に紹介となった．TCSでは，虫垂開口部周囲はSMT様に隆起し，表面は発赤調でイクラ様の顆粒状粘膜を呈していた．NBI併用拡大観察ではI型pit様の腺管開口部周囲の窩間部が開大し，虫垂開口部近傍では顆粒の一部にirregularな血管が観察された．造影CT検査で虫垂の腫大を認めるも，壁外への浸潤や転移を疑う所見はなく，腹腔鏡下右半結腸切除術が施行され，虫垂印環細胞癌と診断された．切除標本の病理組織像との対比から，拡大観察所見は盲腸上皮直下まで進展した虫垂癌を見ていたと考えられた．

　The patient was a female in her 40s. A TCS（total colonoscopy）was performed at a nearby hospital, revealing an abnormality in the cecum. A biopsy that was performed revealed appendix cancer, after which she was referred to our hospital. TCS revealed an area around the appendix opening that was elevated as in case of a submucosal tumor. The surface was reddish with a granular mucous membrane-like appearance similar to salmon roe. Magnifying endoscopy with narrow-band imaging was used and an enlarged type I pit was observed. Irregular blood vessels were observed near the opening of the appendix in some of the granules. Contrast-enhanced computed tomography scan revealed appendix enlargement, without evidence of extramural invasion or metastasis. A laparoscopic right hemicolectomy was then performed and the diagnosis of appendix signet-ring cell carcinoma was made. Comparing the histopathology of the resected specimen with the magnifying endoscopy, we considered the endoscopy to be reflecting the appendiceal carcinoma which had progressed just below the cecal epithelium.