Tumor grading is a system used by doctors to evaluate the appearance of cancer cells under a microscope. It helps determine how aggressive the tumor is and how likely it is to grow and spread. Tumors are typically graded on a scale from 1 to 4, with grade 1 being the least aggressive and grade 4 being the most aggressive. The grade of a tumor can influence treatment decisions and prognosis. For example, a higher-grade tumor may require more aggressive treatment, while a lower-grade tumor might be monitored more closely. Understanding the grade helps patients and doctors make informed choices about care.