抄録
A 75-year-old male turned out positive for the fecal occult blood test without any complaints. A pedunculated but broad-based lesion measuring about 10mm and lacking in mobility was discerned in the sigmoid colon, the top of which assumed an asymmetric and expansive growth. The surface looked uneven and reddened causing haemorrhagic fragility resulting in the formation of depressed erosions and nodules, which was deduced to be indicative of sm2 or deeper cancer. Barium enema likewise revealed no mobility. The entire lesion comprised VI pit, and VN pit was also discerned in depressed portions. Pathologically, well to moderately differentiated cancer (high grade atypia) without adenoma component, cancerous depth sm1, ly0, v0, cut end (－) , interstitial permeation from the bottom of glands present. Despite the features indicative of sm2 or deeper, the lesion resulted in minimally invasive sm1. The present case cautioned us not to make an over-diagnosis between mucosal and sm2 cancer in that there actually exists the limitation or the very difficulty in the clinical diagnosis concerned.
