Adenoma (noncystic)

Appendix
Benign tumors
Adenoma (noncystic)

Author: Jaleh Mansouri, M.D., M.P.H.

Topic Completed: 1 August 2012

Revised: 20 August 2019

Copyright: (c) 2003-2019, PathologyOutlines.com, Inc.

PubMed Search: Adenoma appendix

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Table of Contents

Definition / general | Microscopic (histologic) description

Cite this page: Mansouri J. Adenoma (noncystic). PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/appendixadenoma.html. Accessed October 21st, 2019.

Definition / general

Very rare; by definition, no features of true invasion
Villous adenomas are also called low grade appendiceal mucinous neoplasms
Cystic adenomas are called cystadenomas (see below)
Sporadic, may be associated with colonic adenomas or familial adenomatous polyposis

Microscopic (histologic) description

Resemble colonic tubular, villous or tubulovillous adenomas
Cellular crowding, usually low grade dysplastic changes of nuclear elongation and stratification, pleomorphism and increased mitotic figures
Also mucin depletion
No invasion into appendiceal wall or high grade nuclear atypia