International Classification of Diseases for Oncology, 3rd Edition (ICD-O-3)
Purpose/Definition
Used principally in tumour or cancer registries for coding the site (topography) and the histology (morphology) of neoplasms, usually obtained from a pathology report.
Classification structure
ICD-O is a multi-axial classification of the site, morphology, behaviour, and grading of neoplasms.
The topography axis uses the ICD-10 classification of malignant neoplasms (except those categories which relate to secondary neoplasms and to specified morphological types of tumours) for all types of tumours, thereby providing greater site detail for non-malignant tumours than is provided in ICD-10. In contrast to ICD-10, the ICD-O includes topography for sites of haematopoietic and reticuloendothelial tumours.
The morphology axis provides five-digit codes ranging from M-8000/0 to M-9989/3. The first four digits indicate the specific histological term. The fifth digit after the slash (/) is the behaviour code, which indicates whether a tumour is malignant, benign, in situ, or uncertain (whether benign or malignant).
A separate one-digit code is also provided for histologic grading (differentiation).
Administrative status
Creation date: 1976
Current revision:
ICD-O-3 released 2000
- 1st update, ICD-O-3.1, released 2013
- 2nd update, ICD-O-3.2, released 2019
Change description: Updates in nomenclature and classification, with emphasis on changes on haematologic and neurologic neoplasms.
Reference documents
Available indexes:
A single combined alphabetical index for topography and morphology.
Available formats:
CSV database files are available in WHO download area
Training and training materials:
The European Network of Cancer Registries has provided training courses with the assistance of the International Agency for Research on Cancer, the European Commission and the United States National Cancer Institute.
Languages
Published: Chinese, Czech, English, Finnish, Flemish/Dutch, French German, Japanese, Korean, Portuguese, Spanish, Romanian, Russian, Turkish
Relationship with ICD-11
The morphology content of ICD-O is fully reflected in the histopathology part of ICD-11, as is grading and anatomy. ICD-11 has preserved in its chapter 2, Neoplasms, the anatomical subdivisions of ICD-10 and ICD-O, at the 3-character level. Additional detail is coded, combining codes for anatomy or other aspects of the neoplasm with the code from chapter 2.
An ICD-O view is possible on the ICD-11 maintenance platform.
Relationships with other classifications
- Correspondence tables between ICD-O revisions and between ICD-O revisions and ICD-9 and ICD-10
- Correspondence with international, multinational, national classifications
- The topography classification is essentially that used by ICD-10 for malignant tumours
Relationships – conceptual, structural and other pertinent
Originally based on the American Cancer Society's Manual of Tumor Nomenclature and Coding (MOTNAC), first published in 1951.
Relationships with other terminologies
There is an agreement between the World Health Organization and the College of American Pathologists that the ICD-O morphology classification will be used for the M-8000 to M-9989 codes in the morphology axis of SNOMED. A change of SNOMED in 1993 led to incompatibilities for non-neoplastic lesions. For that reason, ICD-O-3 does no longer include SNOMED codes for non-neoplastic lesions.
Steward/Custodian
The Secretariat / WHO
International Association of Cancer Registries
c/o International Agency for Research on Cancer
E-mail: brayf@who.int; icd@who.int
Contact information:
Mr Freddie Bray
International Agency for Research on Cancer
E-mail: brayf@who.int
Dr Eva Krpelanova
World Health Organization
E-mail: icd@who.int