深達度診断が難しかった0-Is＋IIa型食道癌の1例

Type 0-Is＋IIa Esophageal Cancer with a Difficult-to-assess Depth of Invasion, Report of a Case

要旨　患者は60歳代，男性．胸部中下部食道前壁側に，0-Is＋IIa型食道癌を認めた．左心房の外圧迫上から裏面に位置しており，通常観察では全体像を把握することが難しく，厚みや凹凸を評価しにくかった．拡大観察では病変の大半はtype 3を示し，一部type 4Mを認める程度で，SM深部浸潤を示唆する所見は得られなかった．病理組織診断はT1a-MM/SM1癌の深部に低分化型癌の浸潤部を伴うpSM3で，20MHz細径超音波プローブが最も深達度を客観的に現していた．

　A type 0-Is＋IIa esophageal cancer was noted in the anterior wall of the lower thoracic esophagus of a 60-year-old man. The tumor was compressed by, and located behind, the left atrium. It was difficult to view the entire tumor on conventional endoscopy. The thickness and surface characteristics of the tumor were difficult to assess. On magnifying endoscopy, most of the lesion showed type 3 microvascular pattern, and type 4M vessels were seen in only part of the lesion. There were no findings suggesting deep submucosal invasion. Histopathological examination showed a pSM3, associated with poorly differentiated carcinoma invading the region from the T1a-MM/SM1. 20MHz miniature ultrasound probe showed the depth of invasion most objectively.