Cite this page: Gonzalez RS. WHO classification. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/colontumorwhoclassification.html. Accessed March 28th, 2024.
Definition / general
- WHO classification of tumors of the colon and rectum
- 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
- Serrated dysplasia, low grade 8213/0
- Serrated dysplasia, high grade 8213/2
- Adenomatous polyp, low grade dysplasia 8210/0
- Adenomatous polyp, high grade dysplasia 8210/2
- Tubular adenoma, low grade 8211/0
- Tubular adenoma, high grade 8211/2
- Villous adenoma, low grade 8261/0
- Villous adenoma, high grade 8261/2
- Tubulovillous adenoma, low grade 8263/0
- Tubulovillous adenoma, high grade 8263/2
- Advanced adenoma
- Glandular intraepithelial neoplasia, low grade 8148/0
- Glandular intraepithelial neoplasia, high grade 8148/2
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Malignant epithelial tumors ICD-O codes
- Adenocarcinoma, NOS 8140/3
- Adenoma-like adenocarcinoma 8213/3
- Micropapillary adenocarcinoma 8262/3
- Mucinous adenocarcinoma 8480/3
- Poorly cohesive carcinoma 8490/3
- Signet ring cell carcinoma 8490/3
- Medullary adenocarcinoma 8510/3
- Adenosquamous carcinoma 8560/3
- Carcinoma, undifferentiated, NOS 8020/3
- Carcinoma with sarcomatoid component 8033/3
- Neuroendocrine tumor, NOS 8240/3
- Neuroendocrine tumor, grade 1 8240/3
- Neuroendocrine tumor, grade 2 8249/3
- Neuroendocrine tumor, grade 3 8249/3
- L cell tumor 8152/3
- Glucagon-like peptide producing tumor 8152/3
- PP / PYY producing tumor 8152/3
- Enterochromaffin cell carcinoid 8241/3
- Serotonin producing carcinoid 8241/3
- Neuroendocrine carcinoma, NOS 8246/3
- Large cell neuroendocrine carcinoma 8013/3
- Small cell neuroendocrine carcinoma 8041/3
- Mixed neuroendocrine - nonneuroendocrine neoplasm (MiNEN) 8154/3