粘膜下腫瘍の形態を示した胃癌の超音波内視鏡診断

Diagnosis of Gastric Carcinoma with the Appearance of a Submucosal Tumor of the Stomach, Using Endoscopic Ultrasonography

要旨　粘膜下腫瘍の形態を示した胃癌の超音波内視鏡（EUS）所見について検討した．①粘膜下腫瘍の形態を示すスキルス型胃癌は第3，4層の肥厚を認めスキルス型癌の典型像を示す．②粘膜下腫瘍の形態を示す胃膠様腺癌は第3層に境界明瞭なやや高エコーの腫瘍を認め，迷入膵，脂肪腫との鑑別が可能である．③粘膜下腫瘍の形態を示すlymphoid stromaを伴う胃癌は第3層に境界明瞭な均一低エコーの腫瘤像として認められ，カルチノイド，悪性リンパ腫との鑑別が困難である．④粘膜下囊胞と併存した胃癌は腫瘍の直下の第3層に境界明瞭で類円形の無エコー域を認める．⑤いわゆる粘膜下腫瘍と粘膜下腫瘍の形態を示す胃癌の鑑別診断においてEUSは有用な情報を提供できる．

　We studied the findings concerning gastric carcinoma with the appearance of a submucosal tumor of the stomach, using endoscopic ultrasonography (EUS). Gastric carcinoma with scirrhous invasion with the appearance of a submucosal tumor showed thickening of the 3rd and 4th layers on EUS. Mucinous adenocarcinoma of the stomach with the appearance of a submucosal tumor showed a well-defined and slightly hyperechoic mass in the 3rd layer on EUS. Gastric carcinoma with lymphoid stroma with the appearance of a submucosal tumor showed a well-defined and homogeneous hypoechoic mass in the 3rd layer on EUS. It is difficult to distinguish whether the lesion is carcinoid tumor or malignant lymphoma. Gastric carcinoma accompanied by submucosal cysts with the appearance of a submucosal tumor had a round-shaped and anechoic area beneath the tumor in the 3rd layer on EUS.

　EUS can provide useful information for the differential diagnosis between submucosal tumor and carcinoma with the appearance of a submucosal tumor of the stomach.