All samples are re-coded according to the International Classification of Diseases in Oncology, third edition (ICD-O 3). The codes are used in the SNOMED-CT ontology for malignant disease, too (prefix "M-"). Malignant disease codes always start with either 8 or 9.
For non-malignant samples, a fallback of "0000/0" is used.
See also ICD-O 3 coding.