Richter transformation
Meaning of Richter transformation: A slow leukemia that has been quiet for years turning abruptly into an aggressive lymphoma, usually announced by one rapidly swelling node.
Definition of Richter transformation
Richter transformation is the change of chronic lymphocytic leukemia, or of its tissue-based twin small lymphocytic lymphoma, into an aggressive lymphoma. Diffuse large B-cell lymphoma accounts for most cases and Hodgkin lymphoma for a small minority. Nodes enlarge quickly, fever, drenching sweats and weight loss appear, and the pace of the illness changes over weeks rather than years.
What actually changes?
Chronic lymphocytic leukemia is a slow disease of small, mature-looking B lymphocytes that gather in blood, marrow and nodes over years. In transformation, one cell within that population picks up further genetic damage and begins behaving like a different disease altogether: large cells, rapid division, and growth that outruns its own blood supply. Most transformed lymphomas descend directly from the original leukemic clone and carry the same fingerprint in their antibody genes. A minority turn out to be separate lymphomas that arose independently, and those tend to behave better because they are not built on an already damaged cell.
How is it recognized?
The change announces itself by pace. One group of nodes enlarges far faster than the rest, fevers and drenching night sweats appear, weight falls, and the enzyme lactate dehydrogenase climbs in the blood. Since lymphocytic leukemia enlarges nodes on its own, imaging alone cannot separate the two, and a biopsy of the fastest growing node is what settles it. Scans that show how actively tissue consumes sugar help pick which node to sample, because the change is patchy and a biopsy taken from the wrong site can miss it entirely.
How does it differ from the underlying leukemia?
| Feature | The underlying leukemia | After transformation |
|---|---|---|
| Pace | Years, often watched without treatment | Weeks |
| Nodes | Slow, fairly even enlargement | One area outgrowing the rest |
| Cells down the microscope | Small mature-looking lymphocytes | Large cells dividing fast |
| Lactate dehydrogenase | Usually unremarkable | Rising |
The same event can begin from small lymphocytic lymphoma, which is the identical disease presenting in nodes rather than in blood. Certain features of the leukemia make it more likely beforehand, among them loss of the TP53 gene and antibody genes that never went through their normal maturing step. Outcomes are worse than for the same aggressive lymphoma arising on its own, since the cell it grew from already carried the leukemia's damage.
Also known as
Used in a sentence
Richter transformation was confirmed on biopsy of a rapidly enlarging cervical node.
Good to know
Enlarging nodes occur in the leukemia itself, so transformation is established by biopsy of the fastest growing node rather than by imaging, and the change is patchy enough that a sample from the wrong site can be falsely reassuring.