The patient was a 82-year-old man who had been diagnosed as a non granular type of the so-called laterally spreading tumor, approximately 30mm in size, of the transverse colon by colonoscopy and barium enema 2 years ago. At that time, pathologic examination of the biopsy specimen revealed moderately differenciated adenocarcinoma. He refused to undergo a surgical resection because he underwent sigmoidectomy for the early colorectal cancer 2 years previously. Furthermore 2 years later, colonoscopy and barium enema revealed an invasive tumor exactly at the same site of the transeverse colon, suggesting that the lesion had developed from the non granular type. He underwent the partial resection of the transeverse colon. Pathologic examination of the resected specimen revealed well to moderately differenciated adenocarcinoma without adenomatous component, ss, 31 × 22mm in size. The findings of this case and the cases disgnosed as the non granular type of the laterally spreading tumors in our center, suggest that non granular type invade the submucosal layer, at the size of approximately 20mm and, furthermore invade into the muscular and serosa layer, at the size of approximately 30 mm.
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