Derived Grade

NAACCR Item

NAACCR #1975
Code Description
1 G1: Spindle cell melanoma (>90% spindle cells)
2 G2: Mixed cell melanoma (>10% epithelioid cells and <90% spindle cells)
3 G3: Epithelioid cell melanoma (>90% epithelioid cells)
A Well differentiated
B Moderately differentiated
C Poorly differentiated
D Undifferentiated, anaplastic
9 Grade cannot be assessed (GX); Unknown