Melanosis Coli

Abstract

60-year-old woman with a family history of colon cancer and a history of adenomatous colorectal polyps underwent surveillance colonoscopy. Her last endoscopy, three years previously, had revealed two polyps and normal colonic mucosa (Panel A). Since then, increasing constipation had developed, for which the patient took a daily dose of senna, a laxative that contains anthraquinone. Endoscopy revealed diffuse dark brown and black pigmentation throughout her colon, which is consistent with the presence of melanosis coli (Panel B). Biopsies of the affected areas showed pigment in macrophages of the lamina propria, without any evidence of inflammation or cancer (Panel C).Melanosis coli is dark brown pigmentation of the colon that occurs with the use of laxatives containing anthraquinone, such as senna. It can develop within a few months of use, and it can disappear in a few months if the use of the laxative is discontinued. Anthraquinones have a direct toxic effect on the epithelial cells of the colon that results in the production of lipofuscin, the dark pigment seen in macrophages in melanosis coli (Panel C, arrow). The cecum and rectum are the most common sites of melanosis coli, but it can affect the entire large bowel. Melanosis coli is considered a benign lesion because no association with colorectal cancer has been shown.

Medical complications of bulimia nervosa and their treatments

“…Microscopic melanosis can be seen in about half of patients taking anthraquinone-based laxatives. 27 There is no indication that melanosis coli has any significant pathophysiologic consequences, although there have been reports that phenolphthalein-containing laxatives are carcinogenic in laboratory animals. Thus, they were withdrawn from the market about 10 years ago.…”

Melanosis Coli?

“…to the editor: The summary of the article on fondaparinux for symptomatic pulmonary embolism in This Week in the Journal (Oct. 30 issue) 1 shows the chemical structure of fondaparinux and refers to it as a pentasaccharide. Although it is true that fondaparinux has a pentasaccharide skeleton, its pharmacodynamic activity as a thrombin inhibitor is surely attributable to the eight sulfate groups that make it a polyanion, analogous to heparin.…”

“…The term "melanosis coli" was coined in 1857 by the German pathologist Dr. Rudolf Virchow, who is considered to be the father of modern pathology. 1 Although the correspondents' suggestion that this entity be renamed "nigrosis coli" is worthy of consideration, nearly 150 years of history and entrenchment of the term "melanosis coli" in the gastroenterology and pathology lexicons suggest that the name change is unlikely. …”

Melanosis Coli: Case Report

“…Melanozis koli, antrakinon içeren laksatiflerin kronik kullanılması sonrasında kolonik mukozanın koyu pigmentasyonu ile karakterize bir durumdur. Laksatif kullanımının ilk birkaç ayında ortaya çıkabilir ve laksatiflerin kesilmesinden sonraki ilk birkaç ayda aşama aşama kaybolabilir [1,2]. İntestinal mukozada pigment birikimi konstipasyonun sebebinin araştırılması esnasında endoskopistler tarafından özellikle kolonda yaygın gözlenen bir durumdur.…”

“…Antrakinonlar kolon epitel hücreleri üzerinde direk toksik etkiye sahiptir ve bu melanozis kolide makrofajlarda gözlenen lipofuskin denilen koyu pigmentin üretimi ile sonuçlanır. Çekum ve rektum melanozis kolinin en yaygın görüldüğü yerlerdir fakat kalın barsağın diğer kısımlarını ve ince barsakları da etkileyebilir [1,2,4]. Antrakinon içeren laksatiflerin kolonik epitelyum hücrelerinde bazı organelleri geri dönüşümsüz hasara uğrattığı gözlenmektedir.…”