Primary malignant melanoma of the ascending colon

BMJ Case Rep. 2018 Mar 9:2018:bcr2017223282. doi: 10.1136/bcr-2017-223282.

Abstract

Malignant gastrointestinal melanoma is usually a metastatic lesion. We report the case of a 67-year-old female patient who presented with intermittent abdominal pain, fever, rigor and diarrhoea. CT scan of the abdomen revealed a large mass at the right iliac fossa with features concerning for intra-abdominal abscess. Exploratory laparotomy confirmed the preoperative diagnosis of abscess, and a right hemicolectomy was performed. Histopathological examination of the surgical specimen was indicative of malignant melanoma, and immunohistochemical examination showed positivity to S100 protein, Melan-A, HMB-45 and vimentin. A series of postoperative clinical, laboratory and imaging examinations revealed no suspicious lesions in the skin, eye, leptomeninges or other sites. Therefore, the diagnosis of primary colonic melanoma was confirmed. Only 36 additional cases of primary colonic melanoma have been reported to date. These rare neoplasms are challenging to diagnose and usually require a multidisciplinary treatment approach, including surgery, chemotherapy and possibly immunotherapy or radiotherapy.

Keywords: colon cancer; gastrointestinal surgery; general surgery; pathology; surgical oncology.

Publication types

  • Case Reports

MeSH terms

  • Abdomen / diagnostic imaging*
  • Abdominal Pain / diagnosis
  • Aftercare
  • Aged
  • Biomarkers, Tumor / metabolism
  • Chemotherapy, Adjuvant / methods
  • Colectomy / methods
  • Colon, Ascending / pathology*
  • Colonic Neoplasms / pathology*
  • Colonic Neoplasms / surgery
  • Diarrhea / diagnosis
  • Female
  • Humans
  • Laparotomy / methods
  • MART-1 Antigen / metabolism
  • Melanoma / metabolism
  • Melanoma / pathology*
  • Melanoma / surgery
  • Melanoma-Specific Antigens / metabolism
  • Rare Diseases
  • S100 Proteins / metabolism
  • Tomography, X-Ray Computed
  • Treatment Outcome
  • Vimentin / metabolism
  • gp100 Melanoma Antigen

Substances

  • Biomarkers, Tumor
  • MART-1 Antigen
  • Melanoma-Specific Antigens
  • PMEL protein, human
  • S100 Proteins
  • Vimentin
  • gp100 Melanoma Antigen