villiform architecture is typical Image

ectopic crypts which don't connect to the muscularis mucosa; shortened Image

branching; note uniform nature of cells Image

eosinophilic cytoplasm; tall columnar cells Image

next example Image

oncoytic cyto Image

aberrant crypt formation seen here Image

The term serrated adenoma was first used in 1990 in regards to polyps demonstrating both a serrated hyperplastic-like architecture and adenomatous changes or dysplasia (Longacre). Longacre & Fenoglio-Preiser also distinguished serrated adenomas from mixed polyps, which had previously been considered a chance merging of two independent polyps, one hyperplastic and the other adenomatous. However, serrated adenomas may be mixed and include components resembling sessile serrated adenoma, hyperplastic polyp, or adenoma. Additionally, some serrated adenomas show high-grade dysplastic changes or intramucosal carcinoma

These polyps often have a pedunculated or broad-based polypoid pattern of growth, with a cerebriform or petal-like endoscopic appearance (Matsumoto). Smaller polyps, are often endoscopically indistinguishable from hyperplastic polyps (Jamarillo).

Management of serrated adenomas remains inconclusive due to lack of evidence-based data for this new classification of polyps. The most recent guidelines by the U.S. National Task Force on Colon Cancer recognize the association between the serrated polyp pathway and potentially aggressive lesions, but do not make specific management recommendations.