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