Objective To investigate the dysplastic changes in juvenile polyposis syndrome (JPS)and to compare different morphologic characteristics between solitary colorectal juvenile polyps(JP) and JPS.

• 目的了解我国幼年性息肉病(JPS)不典型增生改变的存在,比较单发结、直肠幼年性息肉(JP)和JPS的不同病理特点。