A Case of Serrated Adenoma Presenting as Colon Cancer

Serrated adenoma (SA) is a distinct form of colorectal neoplasia and it is defined as a neoplastic lesion composed of a monotonous cell population with atypical nuclei proliferating in serrated glandular architectures. Hyperplastic polyp is considered a benign lesion with no malignant potential. However, SA progressed into frank carcinoma has been demonstrated in an individual case, and ‘serrated neoplasia pathway' is suggested by some authors as an alternative to classical adenoma-carcinoma sequence. Distinguishing between hyperplastic polyp and SA is important because of the different management implications and the increased potential for neoplastic progression in the latter, but sometimes it is very difficult. SA is usually small and sessile polypoid lesion. We report a case of SA presenting as large fungating mass similar to colon cancer, diagnosed as hyperplastic polyp initially by colonoscopic biopsy and confirmed as after SA the surgery.