COLONIC CHICKEN SKIN MUCOSA - AN ENDOSCOPIC AND HISTOLOGICAL ABNORMALITY ADJACENT TO COLONIC NEOPLASMS

Objectives: We recently described an endoscopic finding of pale yellow -speckled mucosa adjacent to colonic neoplasms. This resembled the app earance of chicken skin and was named chicken skin mucosa (CSM). CSM d iffers from previously reported gastrointestinal xanthelasmas in that this entity always occurs in association with colonic neoplasms. The p revalence, endoscopic characteristics, clinical significance, and poss ible etiology were investigated, Methods: Eight hundred fifty-two cons ecutive colonoscopies were prospectively evaluated for the presence of CSM associated with either cancer or adenomas greater than or equal t o 1 cm. Electron microscopy and histopathology using hemotoxylin and e osin, mucicarmine, and oil red O stains were performed. Twelve consecu tive colon cancer resection specimens were prospectively examined to d etermine the presence of histologic CSM. Results: CSM was adjacent to eight of 10 distal colorectal cancers, one of four proximal colon canc ers, 16 of 42 distal adenomas, and three of 44 proximal adenomas. Four of seven resected distal cancers demonstrated histological evidence o f CSM. Biopsies of the CSM revealed that lipid-filled macrophages in t he lamina propria were responsible for this endoscopic appearance. Ele ctron microscopy showed that the surface epithelial cells had small in testine-like microvilli. CSM was not seen with other colonic condition s and was not associated with the laxative preparation. In four instan ces, identification of the CSM alerted the endoscopist to the presence of polyps in locations difficult to visualize. Conclusions: CSM is an endoscopic entity that occurs as a result of fat accumulation in macr ophages in the lamina propria of the mucosa adjacent to colonic neopla sms. Small intestine-like microvilli were present in CSM and the patho physiological implications remain to be elucidated. (C) 1998 by Am. Ce ll. of Gastroenterology.