Melanosis coli. Changes in appearance when associated with colonic neoplasia

Arch Surg. 1983 Jan;118(1):62-4. doi: 10.1001/archsurg.1983.01390010048011.


In 30 cases of colonic neoplasia associated with melanosis coli, proliferating or neoplastic colonic epithelium was notable within the melanotic colons by virtue of a striking absence of pigmentation. Microscopically this characteristic was found to be due to an absence or diminution of pigment-laden macrophages in the lamina propria underlying such lesions. Therefore, the absence of pigment-laden macrophages can be considered a marker for abnormally proliferating epithelium. This characteristic may denote a cellular or humoral change mediated by macrophages in association with neoplastic epithelium.

MeSH terms

  • Colonic Diseases / complications*
  • Colonic Diseases / pathology
  • Colonic Neoplasms / complications*
  • Colonic Neoplasms / etiology
  • Colonic Neoplasms / pathology
  • Humans
  • Intestinal Mucosa / pathology
  • Macrophages / pathology
  • Neoplasm Staging
  • Pigmentation Disorders / complications*
  • Pigmentation Disorders / pathology