表在平坦型（0-Ⅱb型）食道癌の1例

Superficial Flat Type (0-Ⅱb) Esophageal Carcinoma, Report of a Case

要旨　46歳，男性．アルコール性肝障害で通院中，食道静脈瘤の有無をみるための内視鏡検査で下部食道に異常所見を発見され入院した．内視鏡検査では，下部食道に低い隆起と，その周辺に発赤した粘膜が認められた．その中に前回の生検の跡と思われる小発赤点があった．病変部はヨード染色法で不染帯としてはっきり描出された．生検診断は扁平上皮癌であった．食道二重造影像では，この生検の跡と思われる小不整陰影斑の周囲に淡いバリウムの付着として現れた．切除標本の肉眼観察では病変を指摘することができなかった．切除標本のヨード染色で病変は2.3×1.5cmの不染帯として現れた．病変部は平坦で，周辺との境界部に高低差はなく表在平坦型（0-Ⅱb型）と診断した．病理組織診断は中分化型扁平上皮癌，深達度mm₁，リンパ節転移は認められなかった．このような平坦型食道表在癌の診断におけるヨード染色法の大切さを再認識した．

　A 46-year-old man was referred to our clinic for a precise examination of the abnormal findings in the lower esophagus, which had been found in the checkup esophagoscopy for esophageal varices.

　Endoscopically, slight elevated lesion and reddish abnormal mucosa were seen in the lower esophagus, and the reddish biopsy site of the previous endoscopy was also observed in this lesion. This area was clearly revealed as anunstained area in iodine staining endoscopy. Squamous cell carcinoma was found in the biopsy specimen.

　Double contrast radiograph in the esophagus showed a faint, irregular barium coated area with a small barium fleck in the lower esophagus.

　Macroscopically, the lesion was not detected in the fresh resecteds pecimen. In the iodine staining of the specimen, the lesion was able to be seen as an unstained area, measuring 2.3×1.5cm. The lesion was diagnosed as superficial flat type (0-Ⅱb) esophageal cancer.

　Histological diagnosis was moderately differentiated squamous cell carcinoma with invasion of the upper part of the lamina propria mucosae (mm₁) without metastasis to the lymphnodes.

　For diagnosis of superficial flat type esophageal carcinoma, the iodine staining method was recognized to be of utmost important.