内視鏡的肉眼病型からみた隆起型食道扁平上皮癌の形態学的特徴と深達度診断に関する検討

Analysis of Macroscopic Tumor Type by Endoscopic Examination as well as the Invasive Depth of Protruding Esophageal Squamous Cell Carcinoma

要旨　隆起形態を示す0-IIa・0-I・1型食道扁平上皮癌について，内視鏡所見を中心とした肉眼病型別の色調および形態学的特徴と病理組織学的所見から，食道癌の壁深達度診断について検討した．隆起型食道癌の病型は，0-IIb，0-IIcを随伴する混合型が主体であるが，癌浸潤最深部の多くは隆起部分に一致していた．0-IIa型では，白色顆粒状および白色扁平低隆起は粘膜癌の代表的病型であり，基部に軽度のくびれを有する赤色小結節状0-IIa型はM2～SM1程度，基部が裾を引く赤色結節状0-IIa型はSM2，SM3を呈した．0-I型は，広基性赤色調0-Is型ではSM深部浸潤癌が多く，亜有茎性赤色調隆起0-Ip型もSM浸潤を呈した．1型については，基部の広い1型はT2・T3の進行癌を呈するが，基部の狭い赤色調1型はSM3～T2を示しており，T3外膜浸潤癌は少ない．また，特殊組織型食道癌は隆起を主体とした形態を示し，類基底細胞癌，内分泌細胞癌（小細胞型）では，腫瘍辺縁が非腫瘍性粘膜上皮に被覆され上皮下に発育する傾向を有し，癌肉腫は亜有茎性ポリープ状隆起を呈するという特徴がある．

　Analysis was made on the diagnosis of invasive depth of esophageal cancer from the color and macroscopic appearance by endoscopic examination of type 0-IIa, 0-1 and type 1, showing protrusion. Most protruding cancers are mixed type, accompanied by 0-IIb and 0-IIc, but the deepest lesion is occasionally located on the protruding portion. The whitey granular and whitish flat elevation of type 0-IIa is a typical feature of mucosal cancer, whereas a reddish tiny granular tumor with gentle sloping of type 0-IIa is limited to the M2 and the SM1. The flat reddish type 0-Is often invading deeply to the SM, and type 0-Ip showing reddish flat elevation with constrictor at the base has invaded to the SM. Type 1 with wide border is invading as progressive cancer of T2 and T3, and the type 1 with reddish feature and small border is limited to the SM3 and the T2 and rarely progressing to T3. Rare pathological esophageal cancers are found mostly as protruding tumors, and pseudobasal cell cancer, endocrine cancer（small cell cancer）show subepithelial growth at the tumor edge covered by normal mucosa, and carcinosarcoma is featured by polyp-like protrusion with constrictor at the base.