Within the gastrointestinal tract, osseous metaplasia is an extremely rare phenomenon. It has only recently been described within a traditional serrated adenoma. Serrated colorectal carcinoma is the end point of the serrated neoplasia pathway. Left sided lesions typically arise from traditional serrated adenomas and represent only 8% of colorectal carcinomas. Herein reported is a case of colorectal adenocarcinoma arising from a traditional serrated adenoma with the rare occurrence of osseous metaplasia within the adenoma. The significance of the finding is discussed.
© 2011 The Author. Pathology International © 2011 Japanese Society of Pathology and Blackwell Publishing Asia Pty Ltd.