Lymphangioma of large intestine: report of ten cases with endoscopic and pathologic correlation

Background: Lymphangioma of the intestinal tracts is extremely rare and usu ally presents as a sessile or pedunculated polyp. The cause of these gross morphologic differences is unknown. The aim of this study was to investigat e the characteristic histopathology of the colonic lymphangiomas in compari son with their endoscopic findings. Methods: Ten colonic lymphangiomas, diagnosed and resected endoscopically b etween 1992 and 1999, were microscopically examined and immunohistochemical ly stained with CD31, CD34, Factor VIII-related antigen, and smooth muscle actin. Results: The characteristic endoscopic finding was a transparent, fluctuati ng sessile (7 cases) or pedunculated (3 cases) polypoid mass with the color of normal colonic mucosa. Proliferative and dilated lymphatic tumor vessel s were found in the colonic mucosa as well as in the submucosa in seven cas es. In three pedunculated lymphangiomas, dilated lymphatics were exclusivel y restricted to the submucosa. The endothelial lining cells stained positiv ely for both CD31 and Factor VIII-related antigen in all 10 cases tested, b ut most cases were negative for CD34. Conclusion: A pedicle does not exclude the endoscopic diagnosis of lymphang ioma and there is a close correlation between its presence and histologic s ubmucosal localization of dilated lymphatic vessels.