Hyperplastic Polyp / Mucosal Hyperplasia of the Appendix

Differential Diagnosis

Appendiceal hyperplastic polyp should be distinguished from appendiceal sessile serrated adenoma using the same features as in the colorectum

Appendiceal Hyperplastic Polyp / Mucosal Hyperplasia	Appendiceal Sessile Serrated Polyp/Adenoma
Bases of crypts straight, regular, frequently pointed	Crypts dilated, branched, occasional horizontal bases
Serrations restricted to upper part of glands	Serrations may involve base
Proliferative zone reliably restricted to base	Proliferative zone frequently irregularly displaced upwards from the base

The distinction may be particularly difficult in the appendix
Both are benign if completely excised and completely sectioned