Grading non-Hodgkin lymphoma

Knowing the grade gives your healthcare team an idea of how quickly the non-Hodgkin lymphoma (NHL) may be growing and how likely it is to spread. This helps them plan your treatment. The grade can also help the healthcare team predict how you might respond to treatment.

To find out the grade of NHL, the pathologist looks at a sample from a lymph node or other tissue under a microscope. The grade is a description of how the cancer cells look and behave compared to normal cells. How different the cancer cells are is described as differentiation.

The different types and subtypes of NHL are usually described as either indolent (low grade, slow growing) or aggressive (high grade, fast growing). Some subtypes of NHL cannot be easily classified as they have features of both indolent and aggressive NHL.

Low grade, or indolent, means that the cancer cells are well differentiated. They look and act much like normal cells.

Low-grade types of NHL tend to grow slowly and usually only cause a few symptoms as they develop. As a result, low-grade types of NHL have often spread to other parts of the body by the time they are diagnosed. They usually spread to the bone marrow and spleen.

Some low-grade types of NHL can change, or transform, into a high-grade type of NHL that needs more aggressive treatment.

High grade, or aggressive, means that the cancer cells are poorly differentiated or undifferentiated. They look and act less normal, or more abnormal.

High-grade types of NHL grow quickly. They tend to spread to lymph nodes or other organs in different parts of the body. High-grade types of NHL usually cause symptoms and need to be treated right away.