隆起を呈した潰瘍瘢痕と酷似したⅡc型早期胃癌の1例

A Cace of Type Ⅱc Early Gastric Cancer simulating Elevated Ulcer Scar

　早期胃癌分類が提唱されて十余年，いまや早期胃癌はさほど珍しくなくなったが，今日においても癌，非癌の鑑別に困惑することがある．これらのうち潰瘍瘢痕との鑑別上最も注意すべきものはⅡcあるいはⅡc＋Ⅲ型早期胃癌である¹⁾．従来，潰瘍瘢痕は陥凹性病変の終末像と考えられ，隆起を呈した潰瘍瘢痕についてはあまり検討されておらず，石川ら²⁾が内視鏡所見から潰瘍瘢痕を陥凹型，平坦型，隆起型に分け検討しているにすぎない．

　著者ら³⁾⁴⁾も隆起を呈した潰瘍瘢痕は臨床的に注意すべき病変であることを報告したが，このたび，隆起を呈した潰瘍瘢痕に酷似したⅡc型早期胃癌を経験したので，若干の考案を加えて報告する．

　Case: a 45-year-old man. Chief complaint: epigastralgia.

　Upright, barium-filled X-ray picture revealed widened angle along with irregular contours of the stomach. In double contrast picture was seen mucosal convergency with an oval tumor-like shadow in the center. Pictures with GTF-A showed on tha posterior wall side near the lesser curvature of the angle a hemispheric small protrusion with marked reddening, surrounded by groove-like excavations. The mucosal folds ceased in their vicinity and their tips showed erosions with shapes as if worm-eaten. Resected stomach revealed at the angle a small hemispheric protrusion, about 7 mm in diameter, toward which the mucosal folds seemed to converge. Their tips tapered around the lesion, forming nests of Ⅱc-like shallow excavations encircling the elevation. Histologic study of a section through the center of the elevation showed a plateau-like protrusion with slight constriction around the base. The protrusion consisted chiefly of hyperplastic epitherium of the fovelolae, and there was nothing to suggest malignancy. Circular depressions around the protrusion showed well-differentiated tubular adenocarcinoma localized within the mucosal layer.

　The present case looked morphologically similar to what Sano classified as Ⅱa+Ⅱc belonging to fringe depression type, but the central protrusion was not Ⅱa but regenerative, hyperplastic nests, constituting the so-called “sanctuary area” within Ⅱc. The present case is thus considered to belong to Ⅱc type early cancer. Ulcer scar has been regarded solely as the terminal picture of the depressed lesion, and hardly any effort has been made in the study of ulcer scar with central elevation. Such an ulcer scar, however, is naturally of benign nature to be strictly differentiated from such a case as was described here. Its recognition seems to be clinically very important.