Grading is a way of classifying lymphoma cells based on their appearance and behaviour when viewed under a microscope. To find out the grade of a tumour, the biopsy sample is examined under a microscope. A grade is given based on how the cancer cells look and behave compared with normal cells (differentiation). This can give the healthcare team an idea of how quickly the cancer may be growing and how likely it is to spread.
Each type of non-Hodgkin lymphoma (NHL) has a unique rate of growth and a particular appearance when looked at under a microscope. The grade of NHL is based on how slowly or quickly the lymphoma is growing and how it is likely to behave. NHL is usually divided into 2 groups:
low-grade or indolent lymphomas
Indolent lymphomas tend to grow very slowly and there often are few symptoms in the beginning. Because of this, indolent lymphomas tend to widespread by the time they are diagnosed, often involving the bone marrow and spleen.
Indolent lymphomas may need little or no treatment for months or even years. They are often treated only when symptoms appear.
Indolent lymphomas can shrink or sometimes seem to disappear with treatment, but they tend to come back.
Indolent lymphomas have a fairly good prognosis. People can live many years, although indolent lymphomas are difficult to cure.
Some indolent lymphomas can change (transform) into more aggressive lymphomas and so need more aggressive treatment.
high-grade or aggressive lymphomas
Aggressive lymphomas grow quickly and tend to spread to lymph nodes or other organs throughout the body.
They usually cause symptoms and need treatment right away. Aggressive lymphomas tend to respond well to treatment.
Aggressive lymphomas can frequently be successfully treated with intensive chemotherapy treatment.
Grading plays an important part in planning NHL treatment and can also be used to help estimate a person’s prognosis (future outcome).
Low-grade or indolent lymphomas are mostly B-cell lymphomas. Some subtypes of NHL cannot easily be classified as indolent or aggressive. For example, some subtypes like mantle cell lymphoma, have features of both indolent and aggressive lymphomas.
|Type of NHL||Indolent lymphomas||Aggressive lymphomas|
Chronic lymphocytic leukemia and small lymphocytic lymphoma
Follicular lymphoma (grades 1 and 2)
Splenic marginal zone lymphoma
Extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma)
Nodal marginal zone lymphoma
Precursor B-lymphoblastic leukemia or lymphoma
B-cell prolymphocytic leukemia
Diffuse large B-cell lymphoma (DLBCL)
Follicular lymphoma (grade 3)
Mantle cell lymphoma
Primary mediastinal large B-cell lymphoma
Intravascular large B-cell lymphoma
Primary effusion lymphoma (PEL)
Cutaneous T-cell lymphoma (mycosis fungoides and Sezary syndrome)
T-cell large granular lymphocytic leukemia
Anaplastic large cell lymphoma – primary cutaneous
Precursor T-lymphoblastic leukemia or lymphoma
T-cell prolymphocytic leukemia
Aggressive NK-cell leukemia
Adult T-cell leukemia/lymphoma (HTLV-1)
Extranodal NK/T-cell lymphoma, nasal type
Angioimmunoblastic T-cell lymphoma
Enteropathy-associated T-cell lymphoma
Peripheral T-cell lymphoma, unspecified
Hepatosplenic T-cell lymphoma
Subcutaneous panniculitis-like T-cell lymphoma
Anaplastic large cell lymphoma – primary systemic
Other lymphoma types
Primary central nervous system (CNS) lymphoma
Post-transplant lymphoproliferative disorder
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