This is the ValueSet that contains all the codes in Observation Codes for Primary Tumor Category (http://hl7.eu/fhir/ig/pcsp/ValueSet/mcode-observation-codes-primary-tumor-vs) and Observation Codes for Primary Tumor Category (http://hl7.eu/fhir/ig/pcsp/ValueSet/mcode-observation-codes-primary-tumor-vs). E.g. what you have to deal with if you get resources containing codes in either of them