Sessile serrated adenoma
The characteristics of sessile serrated adenoma are:
- Sawtooth serrations of the epithelium
- Abundant mucin, similar to hyperplastic polyps
- Basal crypt dilation, with mucous retention, and lateral spread of the crypt bases, commonly described as boot shaped or anchor shaped crypts.
On low magnification, a sessile serrated adenoma may be flat (left) or protuberant (right):
Variations on higher magnification:
Sessile serrated adenoma with crypt crowding and little serration, loss of cytoplasmic mucin and marked cytological atypia.
With elongated crypts.
Minimal deviation dysplasia: architectural changes are subtle with mild crowding of crypts separated by less lamina propria and showing some degree of disorganization.
Minimal deviation dysplasia, showing hypermucinous with some crowding of nuclei, focal hyperchromasia, loss of polarity, mitotic figures (red arrow) and dystrophic mucus cells on the surface (black arrow).
Adenomatous dysplasia, having a ‘top–down’ dysplasia distribution similarly to conventional adenomas.
Low magnification of sessile serrated adenoma with serrated dysplasia, with small packed glandular structures with abundant eosinophilic cytoplasm.
High magnification of sessile serrated adenoma with serrated dysplasia: The dysplastic nuclei are round and vesicular with often prominent nucleoli.
Sessile serrated adenoma with gastric phenotype, characterized by foveolar mucin and round nuclei.
A brief report is sufficient:
|Cecum polyp, polypectomy:|
Sessile serrated adenoma.
Hyperplastic polyp, should not have dilation of crypts, branching of crypts or horizontal glands at the base.
Regarding location, the diagnosis of a sessile serrated adenoma is supported by a location within the proximal colon (cecum, ascending, and transverse colon), while hyperplastic polyps are most common in the sigmoid colon and rectum. However, both may occur throughout the colon.
- Enoch Kuo, M.D., Raul S. Gonzalez, M.D.. Colon - Polyps - Sessile serrated adenoma. PathologyOutlines. Topic Completed: 1 January 2018. Minor changes: 1 October 2020
- Liu, Cheng; Walker, Neal I; Leggett, Barbara A; Whitehall, Vicki LJ; Bettington, Mark L; Rosty, Christophe (2017). "Sessile serrated adenomas with dysplasia: morphological patterns and correlations with MLH1 immunohistochemistry
". Modern Pathology 30 (12): 1728–1738. doi:10.1038/modpathol.2017.92. ISSN 0893-3952.
- "This work is licensed under a Creative Commons Attribution 4.0 International License."
- Torlakovic, Emina Emilia; Gomez, Jose D.; Driman, David K.; Parfitt, Jeremy R.; Wang, Chang; Benerjee, Tama; Snover, Dale C. (2008). "Sessile Serrated Adenoma (SSA) vs. Traditional Serrated Adenoma (TSA) ". The American Journal of Surgical Pathology 32 (1): 21–29. doi:10.1097/PAS.0b013e318157f002. ISSN 0147-5185.
- Author: Adrian C. Bateman, M.B.B.S., M.D.. Colon - Polyps - Hyperplastic polyp. Pathology Outlines. Minor changes: 23 September 2021
- David Driman, MBChB FRCPC. Sessile serrated adenoma of the colon. MyPathologyReport. Updated July 23, 2021