Correspondence

Melanosis Coli?

N Engl J Med 2004; 350:197January 8, 2004

Article

To the Editor:

The Image in Clinical Medicine by Ahmed and Gunaratnam (Oct. 2 issue)1 is not completely accurate regarding the pathophysiological mechanism of melanosis coli and the related terminology. The pigmentation is triggered by deposits of apoptotic cells, which are ingested by adjacent macrophages within the epithelial tissue.2 Those macrophages migrate in the lamina propria, where lysosomes convert the remains of the cells into lipofuscin pigment. Thus, the term “melanosis” may be misleading, since the pigment is not melanin. As a reference to the dark color of the pigment, the term “nigrosis” coli (from the Latin word “niger,” meaning black) would be more appropriate.2 In addition to its association with anthraquinones, nigrosis coli may appear during long-term use (use for a period of more than four months) of bisacodyl. It spontaneously declines within a few years after discontinuation of the laxative.

Didier Mennecier, M.D.
Bertrand Vergeau, M.D.
Begin Military Hospital, 94160 St. Mandé, France
mennecier@hepatoweb.com

2 References

1
Ahmed S, Gunaratnam NT. Melanosis coli. N Engl J Med 2003;349:1349-1349
Full Text | Web of Science | Medline

2
Mennecier D, Nizou C, Moulin O, Ciribilli JM, Vergeau B. Nigroses colique. Presse Med 1999;28:106-106
Web of Science | Medline

Author/Editor Response

We are grateful for the comments of Drs. Mennecier and Vergeau, and we appreciate their clarification of the pathophysiological basis of the development of the colonic mucosal pigmentation seen in our patient. 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.

Naresh T. Gunaratnam, M.D.
Thomas M. Shehab, M.D.
Shazia Ahmed, M.D.
St. Joseph Mercy Hospital, Ann Arbor, MI 48109

1 References