Fig. 1.

Scoring Ki67 using the global unweighted method. This case contained 50% high proliferation tumor and 50% low proliferation tumor; therefore, high-power fields were selected for 2 highly proliferative areas and 2 low proliferative areas. In this case the numbers of positive staining cells were as follows: field 1, 39/100; field 2, 33/100; field 3, 5/100; and field 4, 5/100. This gives a mean Ki67 score of 20.5% and a maximum Ki67 score of 39%.