International Classification of Diseases for Oncology (ICD-O) (3rd ed.)

Now in its third edition the International Classification of Diseases for Oncology (ICD-O) has been used for nearly 25 years as the standard tool for coding diagnoses of neoplasms in tumour and cancer registrars and in pathology laboratories. ICD-O is a dual classification with coding systems for both topography and morphology. The topography code describes the site of origin of the neoplasm and uses the same 3-character and 4-character categories as in the neoplasm section of Chapter II ICD-10.