A rectal biopsy shows pigment-laden macrophages in the lamina propria


#1

A 74 year old woman with longstanding hip osteoarthritis presents complains of constipation and loose stool. She undergoes a sigmoidoscopy. A rectal biopsy shows pigment-laden macrophages in the lamina propria.
What is the most likely cause?

1.Whipple’s disease
2.Laxative abuse
3.Non-steroidal anti inflammatory drugs
4.Crohn’s disease
5.Diverticular disease

summary

The pigment laden macrophages suggest that there is melanosis coli. The most common association is with laxatives. To a lesser extent, melanosis coli is also associated with ulcerative colitis.

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Melanosis coli