Chicken Skin Mucosa in the GI Tract

What is CSM?

The name fits the description in this case of colonic mucosa that looks like chicken skin - Chicken Skin Mucosa (CSM). In the article published in 1998, "Colonic Chicken Skin Mucosa: An Endoscopic and Histological Abnormality Adjacent to Colonic Neoplasms", we are told that this phenomenon is lipid filled macrophages that look like "pale yellow-speckled colonic mucosa". CSM can be likened to xanthelasmas which are the yellowish deposits of fat usually on the eyelids of some people.

Burton Shatz, the author of the above article coined the name to describe the odd looking colon mucosa.

The exact mechanism is unknown, but it is thought that lipids break down in the colonocytes (endothelial cell of the colon mucosa) and are absorbed by macrophages and accumulate under the lamina propria. Since there is no mechanism for the fat to be broke down or transported elsewhere, they continue to collect.

The presence of CSM is relevant because it can draw the endoscopist eye to a lesion. Due to the fact that there are some lesions that get missed, anything that helps the doctor see the small or flat polyps is helpful.

What Does CSM Indicate?

Recent studies show that CSM is an indicator for colon cancer. According to the article, "Colonic Chicken Skin Mucosa is an Independent Endoscopic Predictor of Advanced Colorectal Adenoma," by Eun Ju Chung, et al., CSM is linked to multiple adenomas, villous adenomas, and high-grade dysplasia.

While the connection is known, the "why" is yet to be answered. Since 1998, when CSM was first identified, its recognizable appearance has puzzled researchers and doctors. The question of whether it is mucosal damage or actually connected to the carcinogenic process has not been answered.

The two year research study conducted by the afore mentioned article, had a total of 733 patients. Of those, 225 or 30.7% had CSM. They also kept track of the location in the colon the CSM lesions were found - proximal colon or distal colon.

The study found that there was a compelling dominance of carcinoma in situ and high grade dysplasia in those polyps with CSM than those without CSM. The percentage shows just over twice the amount, 7.1% with CSM versus 3.5% without CSM. There also was an increase in multiple adenomas seen in the CSM patients.

A large percentage of the adenomas, 93.3% were found in the distal colon; splenic flexure, descending colon, sigmoid colon, and rectum. 30.7 percent of the patients with carcinoma or adenoma had CSM. Studies outside of this one has shown that some of the risks for colon cancer are, visceral obesity, metabolic syndrome, IBD, and old age. Chung states that the presence of CSM is not connected to these risk factors, and are most likely an independent finding.

Since macrophages are linked with inflammation, it isn't surprising that there is a connection of CSM, chronic inflammation, and colon cancer. Their theory is that "lipid-laden macrophages move towards the tumor and infiltrate the area around it".

CSM's Connection to Polyps in Children

Not long after the discovery of CSM, in 2001, a study found that polyps in children were often surrounded by the odd looking chicken skin mucosa. Michael J. Nowicki et al, in his article, "Colonic Chicken Skin Mucosa: Association With Juvenile Polyps in Children", tells us that 43% of the polyps removed from the 15 children had CSM. The CSM polyps were larger than the polyps without CSM and were almost (71%) always located in the rectosigmoid area of the colon.

The typical pattern of CSM is to be most concentrated at the base of the polyp stalk, and then becoming less so as it extends from the stalk, and on occasion, the opposite colon wall. This research supported the finding that juvenile polyps with CSM presence is not a precursor to neoplasms, and these children were at no higher risk than the rest of the population for developing colon cancer as adults.

Conclusion

As odd as it sounds, chicken skin mucosa is a colon mucosal condition that actually looks like chicken skin. The lipid filled macrophages surround the base of some polyps. Their presence helps the endoscopist see the polyps, but also can indicate abnormal pathology. Until we know the connection, we can marvel at the quirkiness of our bodies in dealing with colon dysplasia.

Have any of you seen this phenomenon? If so, please tell us of your experience.

References

Chung, Eun Ju et al. "Colonic Chicken Skin Mucosa is an Independent Endoscopic Predictor of Advanced Colorectal Adenoma". 4 July, 2015. Intestinal Research. 10 Oct. 2016. Web.

Nowicki, Michael J. M.D.et al. "Colonic Chicken Skin Mucosa: Association With Juvenile Polyps in Children". Vol. 96 No.3, 2001. The American Journal of Gastroenterology. 10 Oct. 2016. Web.

Shatz, Burton A. et al. "Colonic Chicken Skin Mucosa: An Endoscopic and Histological Abnormality Adjacent to Colonic Neoplasms". Vol. 93, No 4. 12 Jan. 1998. The American Journal of Gastroenterology. Print.