Abstract
A 67 year-old male underwent endoscopic examination because of the positive occult blood test for a type Is lesion to be detected in the sigmoid colon. On the second endoscopic examination, 42 days later, the appearance came to alter very drastically to reveal the two storied arch structure of polyp on polyp measuring 10mm and indicative of sm2 type Is early cancer, no EMR performed. More 20 days later, through detailed magnifying endoscopic examination, the protrusion on the top previously pointed out thoroughly collapsed. Cancer was present at the rising part of the lesion and a depressed territory was discernible on the surface accompanying a central internal concave. After crystal violet staining, pit pattern of type VI was present at the rising part of the lesion, pit pattern of type VI＋VN was admitted in the depression territory and the internal concave. Accordingly, the lesion was concluded as sm2, 3 cancer to be resected by laparoscopically aided colectomy. Pathologically type Is 11×10×4mm, sm2, moderately diff aderoca predominantly but poorly diff aderoca at the outpost of cancer, no adenoma component, ly 2, v1, n1 (＋) , polypoid growth derived. Type Is sm cancer, which should have been diagnosed as sm2 upon close scrutiny even at the initial examination, showed proliferation and collapse resulting in the formation of the depression in the elevation, possibly or probably, associated with the progression to small type 2.
