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Grading
Degree of differentiation and an estimate
of growth rate (mitotic index):
•
Grade I-- 75% to 100% differentiation
•
Grade II-- 50%-75% differentiation
•
Grade III-- 25%-50% differentiation
•
Grade IV-- 0%-25% differentiation
Also based on
•
amount of infiltration and
•
amount of stromal tissue in and
around the tumor