Serrated Polyps, Appendix
Scott R. Owens, MD
Key Facts
Clinical Issues
May present as acute appendicitis
May be incidental finding
If no invasive carcinoma present, prognosis is excellent
Macroscopic Features
Entire appendix should be submitted for histology
Proximal margin should be assessed
Ancillary Tests
Mutations of BRAF and KRAS genes variably present
BRAF mutations do not appear with same significance as “serrated neoplasia” pathway elsewhere in colorectum
Diagnostic Checklist
Assessment of presence or absence of cytological dysplasia is important
 Hematoxylin & eosin shows an appendiceal polyp indistinguishable from colonic sessile serrated adenoma. Note the dilated basal crypts containing abundant goblet cells  . |
 Hematoxylin & eosin shows an appendiceal polyp identical to colonic hyperplastic polyp. Note the small non-dilated basal crypts  and superficial crypts with serrated profiles  . |
TERMINOLOGY
Abbreviations
Sessile serrated adenoma (SSA)
Traditional serrated adenoma (TSA)
Hyperplastic polyp (HP)
Mucinous cystadenoma (MCA)
Synonyms
Sessile serrated polyp (SSP)
Used by some observers in place of SSA
