Tumor grade refers to the degree of abnormality of cancer cells

If a tumor is suspected to be malignant, a doctor removes a sample of tissue or the entire tumor in a procedure called a biopsy. From the biopsy, a pathologist (a doctor who identifies diseases by studying cells under a microscope) can determine whether the tumor is benign or malignant. The pathologist can also identify other characteristics of the tumor cells, including tumor grade and the degree of cell differentiation.