Gallbladder & extrahepatic bile ducts
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: 14 May 2025
Copyright: 2020-2025, PathologyOutlines.com, Inc.
PubMed Search: WHO classification[TIAB] (gallbladder OR extrahepatic bile ducts)
Cite this page: Gonzalez RS. WHO classification. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/gallbladderwhoclassification.html. Accessed September 24th, 2025.
Definition / general
- WHO classification of tumors of the gallbladder and extrahepatic bile ducts
- 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
- Adenoma, NOS 8140/0
- Biliary intraepithelial neoplasia, low grade 8148/0
- Biliary intraepithelial neoplasia, high grade 8148/2
- Intracystic papillary neoplasm with low grade intraepithelial neoplasia 8503/0
- Intracystic papillary neoplasm with high grade intraepithelial neoplasia 8503/2
- Intracystic papillary neoplasm with associated invasive carcinoma 8503/3
- Intraductal papillary neoplasm with low grade intraepithelial neoplasia 8503/0
- Intraductal papillary neoplasm with high grade intraepithelial neoplasia 8503/2
- Intraductal papillary neoplasm with associated invasive carcinoma 8503/3
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Malignant epithelial tumors ICD-O codes
- Adenocarcinoma, NOS: gallbladder extrahepatic bile ducts8140/3
- Adenocarcinoma, intestinal type 8144/3
- Clear cell adenocarcinoma, NOS 8310/3
- Mucinous cystic neoplasm with associated invasive carcinoma 8470/3
- Mucinous adenocarcinoma 8480/3
- Poorly cohesive carcinoma 8490/3
- Intracystic papillary neoplasm with associated invasive carcinoma 8503/3
- Squamous cell carcinoma, NOS 8070/3
- Carcinoma, undifferentiated, NOS 8020/3
- Adenosquamous carcinoma 8560/3
- Cholangiocarcinoma 8160/3
- 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
