Sessile serrated adenoma/polyp
Sessile serrated adenomas/polyps (SSA/P) are among the the most frequent premalignant lesion in the appendix, and proximal colon. They are flat to sessile, measure >5mm and are macroscopically covered with yellowish mucus. Histologically, crypts are distorted, often dilated and with with excess serration near the base. Proliferating epithelial cells are abnormally located, often away from the base of the crypts, but cytological atypia is absent. BRAF mutations are a genetic hallmark and frequently associated with the CpG island methylator phenotype (CIMP)
Bosman FT, Carneiro F, Hruban RH, Theise ND (Eds.)
WHO Classification of Tumours of the Digestive System.
International Agency for Research on Cancer: Lyon 2010
Li SC, Burgart L (2007)
Histopathology of serrated adenoma, its variants, and differentiation from conventional adenomatous and hyperplastic polyps.
Arch Pathol Lab Med 131: 440-5