Melanosis coli – A harmless pigmentation or a precancerous condition?

Melanosis coli is a benign, reversible condition characterized by dark pigmentation of the colonic mucosa, with the most probable etiology of chronic use of anthraquinone laxatives. Thus, due to purgative-induced apoptosis, epithelial cells are phagocytized by macrophages in the lamina propria.
MC has been reported to increase the risk of development of colorectal cancer. A 60-yearold woman presented with diffuse abdominal pain and meteorism. Symptomatology and physical examination was suggestive for intestinal obstruction, but, colonoscopy showed the aspect of melanosis coli. The hystopathological exam confirmed the diagnosis.
Because it has been pointed out an association with colorectal cancer, it is important to have in mind melanosis coli as a possible diagnosis in patients with chronic use of anthranoidcontaining laxatives.