Mucoprotein-containing histiocytes (muciphages) in the rectum.

Mucoprotein-containing macrophages (muciphages) are a common finding in routine rectal biopsies, occurring in about 50% of cases. No correlation was found between their presence and the sex, age, and disease of the patient. They must be distinguished from the cells of Whipple's disease and from lipofuscin-containing macrophages. The origin of the mucoprotein is discussed and rectal epithelial mucin is considered a possible source.