UpToDate
Official reprint from UpToDate®
www.uptodate.com ©2016 UpToDate®

Cap polyposis

Authors
Amy Lo, MD
Young-Mee Lee, MD
Section Editor
John R Saltzman, MD, FACP, FACG, FASGE, AGAF
Deputy Editor
Anne C Travis, MD, MSc, FACG, AGAF

INTRODUCTION

Cap polyposis is a rare condition characterized by mucoid, bloody diarrhea associated with erythematous, inflammatory colonic polyps covered by a cap of fibrinopurulent mucous. The disorder was first described in 1985 and has subsequently been reported in occasional case series [1,2]. Despite its rarity, recognition is important since its clinical symptoms may be similar to inflammatory bowel disease or irritable bowel syndrome.

EPIDEMIOLOGY

The epidemiology of cap polyposis has not been well studied. It occurs predominantly in women, most frequently during the fifth decade of life. However, it has been described in men and women ranging from 12 to 76 years of age [1,3,4].

PATHOGENESIS

The etiology is not well understood. It was initially considered a form of inflammatory bowel disease [1]. Others suggested an infectious origin such as Helicobacter pylori or Escherichia coli O18 [3,5], based in part upon symptomatic and colonoscopic improvement after treatment with antibiotics [3,6,7]. Cap polyposis has also been described following pelvic surgery [5].

A possible association with mucosal prolapse syndrome (MPS) has been suggested based upon similar histologic features [8-10]. In MPS, mucosal prolapse occurs adjacent to tumors, diverticula, and prolapsed colostomies. Similarly, abnormal colonic motility may result in mucosal prolapse at redundant transverse folds resulting in local ischemia, recurrent mucosal trauma, and the development of cap polyposis [11]. Symptomatically, the abnormal colonic motility results in constipation.

PATHOLOGY

Erythematous, pedunculated, or sessile polyps are found typically in the rectosigmoid colon, but may involve the entire colon [12,13]. The polyps are usually located at the apices of enlarged transverse mucosal folds and can number from a few to many [1]. They are often mistaken for inflammatory pseudopolyps. The lesions have a reddish surface with adherent mucous and occasional white specks in the colonic mucosa surrounding them [3,14]. There can be associated central pitting and the typical white mucoid cap. The intervening mucosa is normal. A mild form of the disease has been described characterized by multiple patches of flushed, edematous mucosa separated by normal mucosa [3]. Whether these patients progress to the more classic form is unclear.

      

Subscribers log in here

To continue reading this article, you must log in with your personal, hospital, or group practice subscription. For more information or to purchase a personal subscription, click below on the option that best describes you:
Literature review current through: Nov 2016. | This topic last updated: Wed Sep 28 00:00:00 GMT+00:00 2016.
The content on the UpToDate website is not intended nor recommended as a substitute for medical advice, diagnosis, or treatment. Always seek the advice of your own physician or other qualified health care professional regarding any medical questions or conditions. The use of this website is governed by the UpToDate Terms of Use ©2016 UpToDate, Inc.
References
Top
  1. Williams GT, Bussey HJ, Morson BC. Inflammatory "cap" polyps of the large intestine. Br J Surg 1985; 72:S133.
  2. Tomiyama R, Kinjo F, Kinjo N, et al. Gastrointestinal: cap polyposis. J Gastroenterol Hepatol 2003; 18:741.
  3. Akamatsu T, Nakamura N, Kawamura Y, et al. Possible relationship between Helicobacter pylori infection and cap polyposis of the colon. Helicobacter 2004; 9:651.
  4. Li JH, Leong MY, Phua KB, et al. Cap polyposis: a rare cause of rectal bleeding in children. World J Gastroenterol 2013; 19:4185.
  5. Géhénot M, Colombel JF, Wolschies E, et al. Cap polyposis occurring in the postoperative course of pelvic surgery. Gut 1994; 35:1670.
  6. Shimizu K, Koga H, Iida M, et al. Does metronidazole cure cap polyposis by its antiinflammatory actions instead of by its antibiotic action? A case study. Dig Dis Sci 2002; 47:1465.
  7. Nakagawa Y, Nagai T, Okawara H, et al. Cap polyposis (CP) which relapsed after remission by avoiding straining at defecation, and was cured by Helicobacter pylori eradication therapy. Intern Med 2009; 48:2009.
  8. Konishi T, Watanabe T, Takei Y, et al. Confined progression of cap polyposis along the anastomotic line, implicating the role of inflammatory responses in the pathogenesis. Gastrointest Endosc 2005; 62:446.
  9. Konishi T, Watanabe T, Takei Y, et al. Cap polyposis: an inflammatory disorder or a spectrum of mucosal prolapse syndrome? Gut 2005; 54:1342.
  10. Oriuchi T, Kinouchi Y, Kimura M, et al. Successful treatment of cap polyposis by avoidance of intraluminal trauma: clues to pathogenesis. Am J Gastroenterol 2000; 95:2095.
  11. Bookman ID, Redston MS, Greenberg GR. Successful treatment of cap polyposis with infliximab. Gastroenterology 2004; 126:1868.
  12. Sadamoto Y, Jimi S, Harada N, et al. Asymptomatic cap polyposis from the sigmoid colon to the cecum. Gastrointest Endosc 2001; 54:654.
  13. Isomoto H, Urata M, Nakagoe T, et al. Proximal extension of cap polyposis confirmed by colonoscopy. Gastrointest Endosc 2001; 54:388.
  14. Esaki M, Matsumoto T, Kobayashi H, et al. Cap polyposis of the colon and rectum: an analysis of endoscopic findings. Endoscopy 2001; 33:262.
  15. Isaacson P, Attwood PR. Failure to demonstrate specificity of the morphological and histochemical changes in mucosa adjacent to colonic carcinoma (transitional mucosa). J Clin Pathol 1979; 32:214.
  16. Filipe MI, Mughal S, Bussey HJ. Patterns of mucus secretion in the colonic epithelium in familial polyposis. Invest Cell Path 1980; 3:320.
  17. Filipe MI. Mucins of normal, premalignant and malignant colonic mucosa. In: Progress in cancer research and therapy, Wolman SR, Matromarino AJ (Eds), New York 1984. p.237.
  18. Habib NA, Dawson PM, Krausz T, et al. A study of histochemical changes in mucus from patients with ulcerative colitis, Crohn's disease, and diverticular disease of the colon. Dis Colon Rectum 1986; 29:15.
  19. Ehsanullah M, Filipe MI, Gazzard B. Mucin secretion in inflammatory bowel disease: correlation with disease activity and dysplasia. Gut 1982; 23:485.
  20. Buisine MP, Colombel JF, Lecomte-Houcke M, et al. Abnormal mucus in cap polyposis. Gut 1998; 42:135.
  21. Kajihara H, Uno Y, Ying H, et al. Features of cap polyposis by magnifying colonoscopy. Gastrointest Endosc 2000; 52:775.
  22. Ohkawara T, Kato M, Nakagawa S, et al. Spontaneous resolution of cap polyposis: case report. Gastrointest Endosc 2003; 57:599.
  23. Ng KH, Mathur P, Kumarasinghe MP, et al. Cap polyposis: further experience and review. Dis Colon Rectum 2004; 47:1208.
  24. Chinen T, Misawa T, Yao T, et al. Pedunculated cap polyps preceding the development of cap polyposis: case report. Gastrointest Endosc 2005; 61:338.
  25. Aggarwal R, Gupta P, Chopra P, Nundy S. Rectal cap polyposis masquerading as ulcerative colitis with pseudopolyposis and presenting as chronic anemia: a case study with review of literature. Saudi J Gastroenterol 2013; 19:187.
  26. Kini GP, Murray I, Champion-Young J, et al. Cap polyposis mistaken for Crohn's disease: case report and review of literature. J Crohns Colitis 2013; 7:e108.
  27. Jerome D, 2005, personal communication.
  28. Chang HS, Yang SK, Kim MJ, et al. Long-term outcome of cap polyposis, with special reference to the effects of steroid therapy. Gastrointest Endosc 2012; 75:211.
  29. Kim ES, Jeen YT, Keum B, et al. Remission of cap polyposis maintained for more than three years after infliximab treatment. Gut Liver 2009; 3:325.
  30. Gallegos M, Lau C, Bradly DP, et al. Cap polyposis with protein-losing enteropathy. Gastroenterol Hepatol (N Y) 2011; 7:415.
  31. Maunoury V, Breisse M, Desreumaux P, et al. Infliximab failure in cap polyposis. Gut 2005; 54:313.
  32. Suzuki H, Sato M, Akutsu D, et al. A case of cap polyposis remission by betamethasone enema after antibiotics therapy including Helicobacter pylori eradication. J Gastrointestin Liver Dis 2014; 23:203.
  33. Oiya H, Okawa K, Aoki T, et al. Cap polyposis cured by Helicobacter pylori eradication therapy. J Gastroenterol 2002; 37:463.
  34. Takeshima F, Senoo T, Matsushima K, et al. Successful management of cap polyposis with eradication of Helicobacter pylori relapsing 15 years after remission on steroid therapy. Intern Med 2012; 51:435.
  35. Batra S, Johal J, Lee P, Hourigan S. Cap Polyposis Masquerading as Inflammatory Bowel Disease in a Child. J Pediatr Gastroenterol Nutr 2016.
  36. Arimura Y, Isshiki H, Hirayama D, et al. Polypectomy to eradicate cap polyposis with protein-losing enteropathy. Am J Gastroenterol 2014; 109:1689.
  37. Sasaki Y, Takeda H, Fujishima S, et al. Nine-year follow-up from onset to spontaneous complete remission of cap polyposis. Intern Med 2013; 52:351.