<n0:ComplexDefinition xmlns:n0="http://ncicb.nci.nih.gov/xml/owl/EVS/ComplexProperties.xsd#"><n0:def-definition>A polyp found mainly in the stomach and colon. Microscopically, it is characterized by elongated, serrated crypts lined by proliferative epithelium. Hyperplastic polyps are traditionally considered non-neoplastic, but ras mutation is common, clonality has been demonstrated and biochemical abnormalities and epidemiological associations that occur in colorectal adenomas and carcinomas have been found (WHO Tumors of the Digestive System, 2000).</n0:def-definition><n0:def-source>NCI</n0:def-source></n0:ComplexDefinition>