Korean J Gastroenterol.  2017 Jun;69(6):368-371. 10.4166/kjg.2017.69.6.368.

Malignant Melanoma of the Anus Found during Routine Colonoscopy in Ulcerative Colitis

Affiliations
  • 1Department of Internal Medicine, Kosin University College of Medicine, Busan, Korea. moonone70@hanmail.net

Abstract

Inflammatory bowel disease (IBD) is characterized by recurrent or chronic inflammation of the gastrointestinal tract, which results in increased risk of developing cancer. Anorectal malignant melanoma is often misdiagnosed as either hemorrhoids or benign anorectal conditions in inflammatory bowel disease. Therefore, the overall prognosis and survival of IBD are poor. To date, the best treatment strategy remains controversial. Only early diagnosis and complete excision yield survival benefit. Here, we report a 64-year-old woman with ulcerative colitis, who was found to have anal malignant melanoma on routine colonoscopy. The lesion was confined to the mucosa with no distant metastasis. She underwent complete trans-anal excision. There was no recurrence at the four-year follow-up. Physicians should be aware of increased risk of cancer development in IBD patients and remember the importance of meticulous inspection of the anal canal.

Keyword

Malignant melanoma; Ulcerative colitis; Anus; Colonoscopy

MeSH Terms

Anal Canal*
Colitis, Ulcerative*
Colonoscopy*
Early Diagnosis
Female
Follow-Up Studies
Gastrointestinal Tract
Hemorrhoids
Humans
Inflammation
Inflammatory Bowel Diseases
Melanoma*
Middle Aged
Mucous Membrane
Neoplasm Metastasis
Prognosis
Recurrence
Ulcer*

Figure

  • Fig. 1 Initial colonoscopic findings. (A) At one o'clock direction, a black longitudinal lesion (0.8×0.3 cm) without epithelial break was noted in the anal canal. (B) At seven o'clock direction, a similar sized, ovoid, black lesion was noted within the dentate line.

  • Fig. 2 Pathologic findings. Histopathologic examination revealed both nuclear pleomorphism and cytoplasmic melanin pigmentation in the resected specimen (A, H-E stain, ×100; B, H-E stain, ×200). Immunochemical staining was positive for both S-100 (C, ×200) and HMB45 (D, ×200).

  • Fig. 3 Follow-up colonoscopic findings at four-year follow-up. (A) There was no recurrence of malignant melanoma four years postoperatively. (B) A ~5 mm whitish scar was noted.


Reference

1. Kappelman MD, Farkas DK, Long MD, et al. Risk of cancer in patients with inflammatory bowel diseases: a nationwide population-based cohort study with 30 years of follow-up evaluation. Clin Gastroenterol Hepatol. 2014; 12:265–273.e1.
2. Pei W, Zhou H, Chen J, Liu Q. Treatment and prognosis analysis of 64 cases with anorectal malignant melanoma. Zhonghua Wei Chang Wai Ke Za Zhi. 2016; 19:1305–1308.
3. Ng WK, Wong SH, Ng SC. Changing epidemiological trends of inflammatory bowel disease in Asia. Intest Res. 2016; 14:111–119.
4. Garg SK, Loftus EV Jr. Risk of cancer in inflammatory bowel disease: going up, going down, or still the same? Curr Opin Gastroenterol. 2016; 32:274–281.
5. Shah SB, Pickham D, Araya H, et al. Prevalence of anal dysplasia in patients with inflammatory bowel disease. Clin Gastroenterol Hepatol. 2015; 13:1955–1961.e1.
6. Slesser AA, Bhangu A, Bower M, Goldin R, Tekkis PP. A systematic review of anal squamous cell carcinoma in inflammatory bowel disease. Surg Oncol. 2013; 22:230–237.
7. Singh S, Nagpal SJ, Murad MH, et al. Inflammatory bowel disease is associated with an increased risk of melanoma: a systematic review and meta-analysis. Clin Gastroenterol Hepatol. 2014; 12:210–218.
8. Kim ER, Chang DK. Colorectal cancer in inflammatory bowel disease: the risk, pathogenesis, prevention and diagnosis. World J Gastroenterol. 2014; 20:9872–9881.
9. Abbas AM, Almukhtar RM, Loftus EV Jr, Lichtenstein GR, Khan N. Risk of melanoma and non-melanoma skin cancer in ulcerative colitis patients treated with thiopurines: a nationwide retrospective cohort. Am J Gastroenterol. 2014; 109:1781–1793.
10. Cheung MC, Perez EA, Molina MA, et al. Defining the role of surgery for primary gastrointestinal tract melanoma. J Gastrointest Surg. 2008; 12:731–738.
Full Text Links
  • KJG
Actions
Cited
CITED
export Copy
Close
Share
  • Twitter
  • Facebook
Similar articles
Copyright © 2024 by Korean Association of Medical Journal Editors. All rights reserved.     E-mail: koreamed@kamje.or.kr