title: Melanosis coli. Changes in appearance when associated with colonic neoplasia.
abstract: 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: D003108:Colonic Diseases / Q000150:complications* / Q000473:pathology; D003110:Colonic Neoplasms / Q000150:complications* / Q000209:etiology / Q000473:pathology; D006801:Humans; D007413:Intestinal Mucosa / Q000473:pathology; D008264:Macrophages / Q000473:pathology; D009367:Neoplasm Staging; D010859:Pigmentation Disorders / Q000150:complications* / Q000473:pathology