Code for the best method of diagnostic confirmation of the cancer being reported at any time in the patient’s history.

Diagnostic confirmation is useful to calculate rates based on microscopically confirmed cancers. Full incidence calculations must also include tumors that are only confirmed clinically. The percentage of tumors that not micropscopically confirmed is an indication of whether case finding is including sources outside of pathology reports.

1	Positive histology
2	Positive cytology
3	Positive histology PLUS - positive immunophenotyping AND/OR positive genetic studies (Used only for hematopoietic and lymphoid neoplasms M-9590/3-9992/3)
4	Positive microscopic confirmation, method not specified
5	Positive laboratory test/marker study
6	Direct visualization without microscopic confirmation
7	Radiography and/or other imaging techniques without microscopic confirmation
8	Clinical diagnosis only (other than 5, 6, or 7)
9	Unknown whether or not microscopically confirmed; death certificate only

Note: Code 3 (used only for hematopoietic and lymphoid neoplasms M-9590/3-9992/3) was adopted for use effective with 2010 diagnoses.