Code for the grade or degree of differentiation of the reportable tumor. For lymphomas and leukemias, field also is used to indicate T-, B-, Null-, or NK-cell origin.

Note: Code 8 was adopted for use with lymphoma cases diagnosed in 1995 and later.

Codes  

See the grade tables on page 67 of ICD-O-3.¹⁶ See also the most recent CoC FORDS manual and SEER Program Code Manual, for site specific coding rules and conversions.

1	Grade I
2	Grade II
3	Grade III
4	Grade IV
5	T-cell
6	B-cell
7	Null cell
8	NK (natural killer) cell
9	Grade/differentiation unknown, not stated, or not applicable

Comment: Use the most recent Hematopoietic and Lymphoid rules for assigning grades 5-8.