What is the difference between Hodgkin and non-Hodgkin lymphoma?

The difference comes down to one cell under a microscope. The National Cancer Institute describes Reed-Sternberg cells as "large, abnormal lymphocytes (a type of white blood cell) that may contain more than one nucleus." A pathologist who finds them is looking at Hodgkin lymphoma. A pathologist who does not is looking at non-Hodgkin lymphoma. Both are cancers of the lymph system, which NCI defines as the origin of every lymphoma.

One is a disease, the other is a category

Hodgkin lymphoma is fairly specific. It comes in two main forms, classic and nodular lymphocyte-predominant.

Non-Hodgkin lymphoma is not one disease at all. It is everything that is not Hodgkin. The World Health Organization sorts lymphoid cancers into "three major categories of lymphoid malignancies based on morphology and cell lineage: B-cell neoplasms, T-cell/natural killer (NK)-cell neoplasms, and Hodgkin lymphoma." NCI reports that "B-cell lymphomas make up about 85% of NHL cases," and that follicular lymphoma alone "makes up 20% of all NHL."

So "non-Hodgkin lymphoma" on a report is a starting point, not a diagnosis. The subtype is the diagnosis.

Age differs

NCI says Hodgkin lymphoma is most common in people ages 20 to 39 and in people 65 and older.

The outlook, and a genuine surprise

For Hodgkin lymphoma, NCI states that "up to 90% of all newly diagnosed patients with HL can be cured with combination chemotherapy and/or radiation therapy."

For non-Hodgkin lymphoma there is no single figure, because the subtypes behave so differently. NCI splits them into indolent and aggressive, and what follows is not what most people expect.

Indolent means slow growing. NCI says "indolent NHL has a relatively good prognosis, with a median survival as long as 20 years, but it is usually not curable in advanced clinical stages."

Aggressive means fast growing. NCI says "aggressive NHL has a worse prognosis in the short term, but a significant number of patients can be cured."

Read those together. The slow lymphoma often cannot be cured but can be lived with for decades. The fast one is more dangerous in the near term and more often ends in cure. Fast-dividing cells are the ones chemotherapy hits hardest, which is why speed cuts both ways.

What to ask your care team for

If you or someone close to you has been told non-Hodgkin lymphoma, that phrase is not enough to plan around. Ask for two more things: the full subtype name as written on the pathology report, and whether the team considers it indolent or aggressive.

Those two answers determine whether the conversation ahead is about curing something quickly or managing something for years. They are different conversations, and the label on its own does not tell you which one you are in.