生検でGroup IIのため経過観察され悪性サイクルを呈した0-IIc型早期胃癌の1例

A Case of Early Gastric Cancer Representing “Malignant Cycle”, Followed by Repeated Endoscopy on the Basis of Group II Pathological Findings

要旨　内視鏡的に胃癌を疑いながらも生検で癌が証明されないことは内視鏡医の多くが経験し悩むところである．内視鏡的に悪性サイクルを繰り返した0-IIc型早期胃癌の症例を提示する．内視鏡的に悪性が疑われたが，生検では癌の診断に至るのに時間を要した．繰り返し生検を行ったが，Group IIとの診断にとどまった．診断的ESDの同意が得られず6回目の生検でGroup Vの診断に至りESDを行った．切除標本では粘膜固有層の中～下部で手つなぎ・横這い型の構造を示す中分化型腺癌であった．生検で粘膜深部の腫瘍腺管がとらえにくかったことが生検診断を困難にしたと考えられた．

　A 68-year-old woman was examined by screening upper gastrointestinal endoscopy and a reddish slightly elevated lesion was pointed out at the posterior wall of the middle gastric body. Biopsy specimens showed mild atypical glands and were diagnosed as Group II. Endoscopic examination was repeated several times because the lesion was strongly suspected to be an early gastric cancer but the examinations could not prove any obvious pathological cancer. Recurrent ulcer and scar formation-malignant cycle-had been seen for eighteen months. A diagnostic ESD was recommended but the patient refused. The biopsy specimens at the sixth endoscopic examination revealed it to be a moderately differentiated adenocarcinoma. Then ESD was performed. The depth of the cancer was submucosal（220m）. In this case, the reason why the diagnosis of cancer was difficult was that the cancer consisted of “hands-shaking” glands in the middle to deep mucosal layer, where as the biopsy specimens were taken from only the upper-to-middle layer.