Features of high grade dysplasia:
(1) nuclear stratification reaches and involves the mucosal surface (involves the entire gland crypt)
(2) loss of nuclear polarity, with the nucleus no longer perpendicular to the basement membrane lining the crypt
(3) definite immunostaining of the surface epithelium with Ki-67 and/or p53
(4) disappearance of goblet and mucous cells in affected glands
(5) marked nuclear atypia with (a) nuclear enlargement, (b) hyperchromasia, (c) increased mitotic activity, (d) abnormal mitoses
(6) marked architectural distortion and disorganization with (a) branching of crypts, (b) lateral budding of crypts, (c) villiform configuration of the villous surface, (d) fused and back-to-back glands.
If high grade dysplasia is identified then it is important to make sure that invasive carcinoma is not present.
