A prospective clinicopathological and endoscopic evaluation of flat and depressed colorectal lesions in the United Kingdom

OBJECTIVES:Flat and depressed colorectal lesions are now reported in Western populations. The malignant potential, anatomical distribution, and other clinicopathological features have not been established in this group. This study aimed to assess prospectively the prevalence, clinicopathological, and endoscopic features of flat and depressed colorectal lesions in the United Kingdom.METHODS:A single endoscopist performed colonoscopy on 850 consecutive patients presenting for routine colonoscopy. All endoscopies were performed using a high magnification colonoscope with chromoscopy to facilitate detection of flat and depressed colorectal lesions.RESULTS:A total of 458 flat lesions were identified. Of these, 173 (38%) were hyperplastic and 285 (62%) adenomatous or beyond. Of the 173 hyperplastic flat lesions, 162 (94%) were located in the recto-sigmoid region. Of the 267 adenomas, 66 (25%) had areas of high grade dysplasia (HGD), with 54/66 (82%) being present in the right colon. Flat lesions <8 mm in diameter was more likely to contain HGD than those <8 mm (p < 0.001). Nine of the 10 (90%) flat invasive adenoacarcinomas were in the right colon and all had a depressed morphological component. In contrast, HGD was observed in 58/466 (12%) of protuberant (sessile/pedunculated) adenomas of which 95% (55/58) were located in the left colon. In addition, HGD was present in 17% of all sessile adenomas versus 44.6% of flat lesions >8 mm in diameter (p = 0.001). Of the 14 protuberant carcinomas, 13/14 (93%) were in the left colon. Synchronous lesions were found in 96/816 (12%) of cases. Of the 816 patients with two or more left-sided protuberant adenomas <8 mm (with or without HGD), 89 (11%) had one or more flat lesions in the right colon with HGD.CONCLUSIONS:Flat adenomas and carcinomas have a high malignant potential compared to protuberant lesions and have a propensity for developing in the right hemi-colon. Total colonoscopy is required to detect such lesions, as only 18% of flat lesions would be in reach of the flexible sigmoidoscope.

[1]  T. Muto,et al.  Small “flat adenoma” of the large bowel with special reference to its clinicopathologic features , 1985, Diseases of the colon and rectum.

[2]  Y Morioka,et al.  Clinicopathologic features of the flat adenoma , 1991, Diseases of the colon and rectum.

[3]  E T Stewart,et al.  Randomized comparison of surveillance intervals after colonoscopic removal of newly diagnosed adenomatous polyps. The National Polyp Study Workgroup. , 1993, The New England journal of medicine.

[4]  B. Jiang.  Chromoendoscopy and high-magnification colonoscopy in early detection of colorectal cancer. , 2002, Di 1 jun yi da xue xue bao = Academic journal of the first medical college of PLA.

[5]  J. Faivre,et al.  Adenoma‐carcinoma sequence or “de novo” Carcinogenesis?. A study of adenomatous remnants in a population‐based series of large bowel cancers , 1992, Cancer.

[6]  A. Sonnenberg,et al.  Prevention of Colorectal Cancer by Flexible Endoscopy and Polypectomy: A Case-Control Study of 32 702 Veterans , 1995, Annals of Internal Medicine.

[7]  R. Kiesslich,et al.  Chromoendoscopy with Indigocarmine Improves the Detection of Adenomatous and Nonadenomatous Lesions in the Colon , 2001, Endoscopy.

[8]  S. Kudo,et al.  Depressed Type of Colorectal Cancer , 1995, Endoscopy.

[9]  K. Okita,et al.  Endoscopic therapy for early colon cancer: the strip biopsy resection technique. , 1991, Gastrointestinal endoscopy.

[10]  T. Fujii,et al.  Flat and depressed colonic neoplasms: a prospective study of 1000 colonoscopies in the UK , 2000, The Lancet.

[11]  S. Franceschi,et al.  Early diagnosis and prevention of sporadic colorectal cancer. , 2001, Endoscopy.

[12]  Ming-Yao Su,et al.  Magnifying colonoscopy in differentiating neoplastic from nonneoplastic colorectal lesions , 2001, American Journal of Gastroenterology.

[13]  A. Munakata,et al.  The discrepancy of histologic diagnosis between flat early colon cancers and flat adenomas. , 1994, Gastrointestinal endoscopy.

[14]  H. Tajiri,et al.  Assessment of colorectal lesions using magnifying colonoscopy and mucosal dye spraying: can significant lesions be distinguished? , 2001, Endoscopy.

[15]  D. P. Hurlstone,et al.  Early detection of colorectal cancer using high‐magnification chromoscopic colonoscopy , 2002, The British journal of surgery.

[16]  A. Zauber,et al.  Prevention of colorectal cancer by colonoscopic polypectomy. The National Polyp Study Workgroup. , 1993 .

[17]  R. Riddell,et al.  Problems arising from Eastern and Western classification systems for gastrointestinal dysplasia and carcinoma: are they resolvable? , 1998, Histopathology.

[18]  C. Rubio,et al.  Flat adenomas and flat adenocarcinomas of the colorectal mucosa in Japanese and Swedish patients , 1995, Diseases of the colon and rectum.

[19]  D. Owen,et al.  Flat adenomas of the colon. , 1991, Human pathology.

[20]  J Cuzick,et al.  Long-term risk of colorectal cancer after excision of rectosigmoid adenomas. , 1992, The New England journal of medicine.

[21]  J. Watari,et al.  Invasion depth diagnosis of depressed type early colorectal cancers by combined use of videoendoscopy and chromoendoscopy. , 1998, Gastrointestinal endoscopy.

[22]  C. Rubio,et al.  Histologic differences between flat tubular colorectal neoplasias in Japan and Sweden. , 1997, In vivo.

[23]  Syed G. Shah,et al.  Total colonic dye-spray increases the detection of diminutive adenomas during routine colonoscopy: a randomized controlled trial. , 2002, Gastrointestinal endoscopy.

[24]  S. Kudo,et al.  Pit pattern in colorectal neoplasia: endoscopic magnifying view. , 2004, Endoscopy.

[25]  Shin-ei Kudo,et al.  Colonoscopic Diagnosis and Management of Nonpolypoid Early Colorectal Cancer , 2000, World Journal of Surgery.

[26]  M. Stolte,et al.  Colorectal Mini-De Novo Carcinoma: A Reality in Germany Too , 1995, Endoscopy.

[27]  安達 実樹.  Flat Adenoma of the Large Bowel : Re-Evaluation with Special Reference to Central Depression , 2000 .

[28]  Anthony N Kalloo,et al.  Prevalence and distinctive biologic features of flat colorectal adenomas in a North American population. , 2002, Gastroenterology.

[29]  B. Veress,et al.  Flat and depressed colorectal tumours in a southern Swedish population: a prospective chromoendoscopic and histopathological study , 2002, Gut.

[30]  S. Kudo,et al.  Endoscopic Mucosal Resection of Flat and Depressed Types of Early Colorectal Cancer , 1993, Endoscopy.

[31]  A. Iwashita,et al.  Invasive colon cancer derived from a small superficial depressed cancer , 2000, Diseases of the colon and rectum.

[32]  T. Muto,et al.  The evolution of cancer of the colon and rectum , 1975, Cancer.

[33]  C. Rubio,et al.  Flat neoplastic lesions of the colon and rectum detected by high-resolution video endoscopy and chromoscopy. , 1995, Gastrointestinal endoscopy.

[34]  T. Smyrk,et al.  Differential diagnosis of hereditary nonpolyposis colorectal cancer (Lynch syndrome I and Lynch syndrome II) , 1988, Diseases of the colon and rectum.

[35]  T. Smyrk,et al.  Hereditary flat adenoma syndrome: A variant of familial adenomatous polyposis? , 1992, Diseases of the colon and rectum.

[36]  T. Muto,et al.  Morphogenesis of human colonic cancer , 1983, Diseases of the colon and rectum.

[37]  B. Morson.  The Polyp-Cancer Sequence in the Large Bowel , 1974, Proceedings of the Royal Society of Medicine.

[38]  K. Haruma,et al.  Pit pattern diagnosis of early colorectal carcinoma by magnifying colonoscopy: clinical and histological implications. , 2000, International journal of oncology.

[39]  M F Dixon,et al.  The Vienna classification of gastrointestinal epithelial neoplasia , 2000, Gut.

[40]  A. Munakata,et al.  The non-lifting sign of invasive colon cancer. , 1994, Gastrointestinal endoscopy.