California Cancer Reporting System Standards Volume I: Abstracting and Coding Procedures for Hospitals
Use the higher grade when different terms are used for the degree of differentiation as follows:
Term |
Grade |
Code |
Low grade |
I-II |
2 |
Medium grade; intermediate grade |
II-III |
3 |
High grade |
III-IV |
4 |
Partially well differentiated |
I-II |
2 |
Moderately undifferentiated |
III |
3 |
Relatively undifferentiated |
III |
3 |
Occasionally a grade is written as "2/3" or "2/4" meaning this is grade 2 of a 3-grade system or grade 2 of a 4-grade system, respectively.
To code in a three grade system, refer to the following codes:
Histological Grade |
Nuclear Grade |
Description |
Code |
1/3, or I/III |
1/2, 1/3 |
Low Grade |
2 |
2/3, or II/III |
2/3 |
Medium Grade |
3 |
3/3, or III/III |
2/2, 3/3 |
High Grade |
4 |
To code in a two-grade system, refer to the following codes:
Histological Grade |
Nuclear Grade |
Code |
1/2, or I/II |
Low Grade |
2 |
2/2, or II/II |
High Grade |
4 |
See Section V.3.5.11 Grade Path Value
See Section V.3.5.12 Grade Path System