non-Hodgkin lymphoma
Meaning of non-Hodgkin lymphoma: Named for what it is not, this family of lymphocyte cancers spans many separate diseases with very different growth rates and outlooks.
Definition of non-Hodgkin lymphoma
Non-Hodgkin lymphoma is a group name for the many cancers that begin in lymphocytes, the white blood cells of the lymphatic system, and that are not Hodgkin lymphoma. The diseases it covers arise from different cell types, most often B cells, and range from slow growing to fast growing, so the label describes a family rather than a single illness.
How is it different from Hodgkin lymphoma?
The difference is settled under the microscope. Classical Hodgkin lymphoma contains large abnormal cells with a mirrored double nucleus, called Reed-Sternberg cells. Lymphomas that lack them were gathered under one heading, so the name records an absence rather than anything the diseases share. Cells resembling Reed-Sternberg cells can appear in other illnesses, so appearance alone does not decide the matter, and stains that identify the proteins on the cell surface confirm which disease is present. Hodgkin lymphoma is itself now known to arise from B cells, which makes the old dividing line more a naming convention than a biological wall, and current classifications name the specific lymphoma rather than stopping at the broad heading.
What do indolent and aggressive mean?
Growth rate is the first thing described about a new lymphoma, because it shapes everything that follows. The two patterns behave almost in opposite ways.
| Indolent | Aggressive | |
|---|---|---|
| Pace | Slow, sometimes over years | Fast, over weeks or months |
| Symptoms early on | Few or none | Usually noticeable |
| Examples | Follicular lymphoma, small lymphocytic lymphoma | Diffuse large B-cell lymphoma, Burkitt lymphoma |
| Course | Long lived, tends to come back | Responds quickly, more often cured outright |
An indolent lymphoma may be monitored while it causes no trouble, whereas an aggressive lymphoma is acted on without delay. An indolent disease can also change character over time and begin to behave aggressively.
What are the usual signs?
Painless swelling of one or more lymph nodes, in the neck, armpit or groin, is the most common first sign. Nodes deeper in the chest or abdomen can grow large before anything is noticed and may press on nearby structures instead, causing cough, breathlessness or a full feeling in the abdomen. Fever, drenching night sweats and unexplained weight loss are grouped together as B symptoms and are recorded when the disease is staged. Fatigue and itching occur as well. None of these is specific to lymphoma, and swollen nodes follow ordinary infection far more often.
How is it diagnosed?
Tissue is needed. Removing a whole node, or a substantial core of one, preserves the architecture a pathologist reads, which a fine needle sample generally cannot. The tissue is examined under the microscope and then tested for surface markers and for the genetic changes that identify the exact subtype. Imaging and a bone marrow sample show how far the disease has spread. Blood tests support the picture but cannot make the diagnosis on their own.
Used in a sentence
A lymph node biopsy confirmed a diagnosis of non-Hodgkin lymphoma of B-cell origin.
Good to know
Reed-Sternberg cells characterize classical Hodgkin lymphoma, and their absence is the traditional dividing line, but similar looking cells occur in other conditions, so immunostaining rather than appearance alone decides which lymphoma is present.
Word origin
Where “non-Hodgkin lymphoma” comes from
Lymphoma joins Latin lympha, meaning clear water, with the Greek suffix -oma, meaning swelling or tumor; Hodgkin is a surname, and non- marks the exclusion.