Diffuse Melanosis in Pericolic Lymph Nodes Associated With Laxative Abuse and Colorectal Cancer

Abstract

Melanosis coli is an entity described for the first time in 1847 by Virchow and is characterized by the presence of lipofuscin pigment in macrophages of the colonic lamina propria, found in most of the cases in patients who overuse anthracene laxatives.Its etiology, however, has yet not been elucidated, although correlations with drug use (hydralazine, furosemide, hydrochlorothiazide, propranolol, and iron supplements) and systemic diseases (hypertension, chronic renal disease, gastric hemorrhage, and diabetic mellitus) have been evidenced. 1 Figure 1. (A) Pericolic lymph node showing massive presence of macrophages filled with brown, granular pigment (EE, 3×, inset 10×). (B) Immunoreactivity for CD68 confirmed the macrophage nature of the elements (10×).