Final answer:
Grading of a tumor requires a pathologic assessment of the level of cellular differentiation.
Step-by-step explanation:
Grading of a tumor does indeed require a pathologic assessment of the level of cellular differentiation, so the statement is TRUE. When pathologists grade a tumor, they examine the tumor cells under a microscope and determine how closely they resemble normal, healthy cells. The more differentiated, or similar, the tumor cells are to healthy cells, the lower the grade of the tumor. On the other hand, poorly differentiated tumor cells that differ significantly from healthy cells indicate a higher grade tumor.