Table 2 Tumor classification criteria and respective classifications (Couto et al. 2002)

Differentiation

1 - Highly differentiated tumors

2 - Intermediately differentiated tumors

3 - Poorly differentiated tumors

Necrosis

1 - No necrosis

2 - Moderate necrosis (less than 50% of the tumor area)

3 - Extensive necrosis (more than 50% of the tumor area)

Mitotic Index

1 - Highly differentiated tumors

2 - Intermediately differentiated tumors

3 - Poorly differentiated tumors

Inflammatory Infiltrate

0 - No inflammatory infiltrate

1 - Low number of lymphocytes with low or absent follicular formation

2 - Presence of lymphocytes in less than 50% of the peritumoral area, diffusely distributed or forming small follicles

3 - Presence of lymphocytes and follicles in all fields adjacent to the tumor

Giant Cells

0 - No giant cells

1 - Presence of giant cells