Anus & perianal area
General
WHO classification
Author: Raul S. Gonzalez, M.D.
Editor-in-Chief: Debra L. Zynger, M.D.
Last author update: 10 December 2020
Last staff update: 22 February 2024
Copyright: 2020-2024, PathologyOutlines.com, Inc.
PubMed Search: WHO classification anus
Cite this page: Gonzalez RS. WHO classification. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/anuswhoclassification.html. Accessed December 30th, 2024.
Definition / general
- WHO classification of tumors of the anal canal
- Currently on 5th edition, published in 2019
- Based on histologic appearance, not molecular characteristics
WHO (2019)
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Benign epithelial tumors and precursors ICD-O codes
- Squamous intraepithelial neoplasia, low grade 8077/0
- Squamous intraepithelial neoplasia, high grade 8077/2
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Malignant epithelial tumors ICD-O codes
- Squamous cell carcinoma, NOS 8070/3
- Adenocarcinoma, NOS 8140/3
- Neuroendocrine tumor, NOS 8240/3
- Neuroendocrine tumor, grade 1 8240/3
- Neuroendocrine tumor, grade 2 8249/3
- Neuroendocrine tumor, grade 3 8249/3
- Neuroendocrine carcinoma, NOS 8246/3
- Large cell neuroendocrine carcinoma 8013/3
- Small cell neuroendocrine carcinoma 8041/3
- Mixed neuroendocrine - nonneuroendocrine neoplasm (MiNEN) 8154/3
