International Classification of Diseases for Oncology
The International Classification of Diseases for Oncology (ICD-O) is a domain-specific extension of the International Statistical Classification of Diseases and Related Health Problems for tumor diseases. This classification is widely used by cancer registries.
It is currently in its third revision (ICD-O-3). ICD-10 includes a list of morphology codes. They stem from ICD-O second edition (ICD-O-2) that was valid at the time of publication.
The classification has two axes: topography and morphology.
The morphology axis is for the shape and structure of the tumor.
This axis has particular importance because the Systematized Nomenclature of Medicine ("SNOMED") has adopted the ICD-O classification of morphology. SNOMED has been changing continuously, and several different versions of SNOMED are in use. Accordingly, mapping of ICD-O codes to SNOMED requires careful assessment of whether entities are indeed true matches.
The topography axis is for of the tumor's site in the body. It is standardized with the C section of ICD-10.
There were no changes in the topography axis between ICD-O-2 and ICD-O-3.
See List of ICD-10 codes#(C00–C97) Malignant Neoplasms for examples.
M8000/1 Neoplasm, uncertain whether benign or malignant
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