A CASE REPORT OF TYPE IIc+Is RECTAL CANCER IN ADENOMA

Abstract

A 56-year-old man was referred to colonoscopy because of lower abdominal pain. The magnifying colonoscopic examination revealed a type 0'-IIc+Is rectal tumor, 11.8×8.2×3.4 mm in size, showing IIIs pit with amorphism at the depressed (IIc) area and IV pit without amorphism at the protruded (Is) area. Endoscopic mucosal resection was performed, and histological examination revealed well differentiated adenocarcinoma (high and low grade) with minimal submucosal invasion at the IIc area, and tubular adenoma at the Is area. Immunohistochemical study showed that diffuse to focally aggregated staining for p53 at the IIc area and few positive cells at the Is area. Ki-67 positive cells were distributed throughout the whole part of the tubules of adenomatous part (Is) and high grade carcinoma (IIc), but they were confined to the only mucosal upper part at low grade carcinoma (IIc). No K-ras colon 12 mutation was detected within both areas by PCR-RFLP method. The histogenesis and morphogenesis of this tumor were discussed.