術前診断が困難であった超高分化型早期胃癌の1例

Highly Well-differentiated Early Gastric Cancer Causing Difficulty in Preoperative Diagnosis, Report of a Case

要旨　患者は54歳，女性．胃腫瘤の精査目的で当科受診．胃X線検査，内視鏡検査では胃角部大彎に，頂上部に潰瘍を伴った，なだらかな立ち上がりを示す，正常粘膜に覆われた粘膜下腫瘍様の腫瘤を認めた．腫瘤からの生検病理組織像では癌と診断できなかったが，臨床的に癌の粘膜下発育を疑い胃亜全摘を施行した．切除標本の病理組織学的検討では，隆起は超高分化型腺癌の粘膜下層への浸潤とその周囲の線維化により形成されていた．

　A 54-year-old woman was referred to our clinic for further examination of a gastric tumor. Rentgenographic and endoscopic examinations revealed a submucosal-like elevated lesion sloping up gently and covered with normal mucosa with ulceration at the top on the greater curvature of the angular portion of the stomach. Histopathology of biopsied specimens obtained from the tumor was unable to verify a diagnosis as adenocarcinoma. Subtotal gastrectomy was performed since the possibility of a malignant neoplasm could not be excluded clinically. Histopathology of the resected specimen revealed that the lesion was formed by the submucosal invasion of highly well-differentiated adenocarcinoma with neighboring fibrosis.