Transformed Lymphomas
About Transformed Lymphomas
The numerous types of non-Hodgkin lymphomas can be generally classified (grouped) as being either indolent (slow-growing) or aggressive (fast-growing). Indolent lymphomas are usually considered chronic diseases (conditions that can usually be controlled but not cured and require ongoing medical care) that may be successfully managed over years or decades in most patients.
Transformed lymphoma occurs when genetic mutations (permanent changes) in the DNA (deoxyribonucleic acid, the molecule that carries genetic information within the cell) in some indolent lymphoma cells cause them to grow faster and behave more aggressively. Not all of the indolent lymphoma cells undergo transformation at once. When examined under the microscope, biopsies (samples of lymph nodes) from patients with transformed lymphomas will usually have a combination of indolent and aggressive (“transformed”) lymphoma cells. If the number of fast-growing cells increases, the lymphoma can begin to behave more like an aggressive type (grows faster). Compared to indolent lymphomas, this transformed lymphoma usually requires more intensive types of treatment.
One example is Richter syndrome (also called Richter transformation), a rare condition where chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) changes into a fast-growing type of lymphoma.
The physician will choose a treatment that can work for both indolent and aggressive lymphomas, with the goal of eradicating the disease (get rid of it completely), because it can become life-threatening. DLBCL requires treatments that are more intensive and are given more urgently.
Indolent Lymphoma | Transformed Lymphoma |
CLL/SLL | DLBCL (Richter syndrome) Hodgkin lymphoma (uncommon) |
FL (grades 1-2) Grade 1-3A FL are low-grade (slow growing) lymphomas. Grade 3B is treated as high-grade (fastgrowing) lymphoma. | DLBCL High-grade lymphoma with mutations in the MYC and BCL2 and/or BCL6 genes (a piece of DNA that contains information needed to produce the MYC and BCL2 proteins, respectively). This type is also known as double hit lymphoma. |
WM | DLBCL |
MZL | DLBCL |
Nodular lymphocyte-predominant HL (also called nodular lymphocyte predominant B-cell lymphoma) | DLBCL |
Multiple risk factors associated with transformation have been identified. However, the presence of a risk factor does not mean that the lymphoma will transform. The risk factors for FL transformation include:
- Bulky disease (a large tumor)
- High grade FL
- High-risk group based on prognostic scoring systems such as the International Prognostic Index (IPI) and the Follicular Lymphoma International Prognostic Index (FLIPI).
The overall risk of developing a transformed lymphoma is low among patients with an indolent disease, with an average risk of 2 to 3% per year that may stabilize (no longer increase) beyond 6 to 12 years after diagnosis. This means that the majority of these patients will never develop a transformed lymphoma. Many studies have shown that the risk of patients with indolent follicular lymphoma progressing to transformed lymphoma was no different whether they were initially treated with chemotherapy or followed with active surveillance (observation). However, the use of rituximab was associated with a lower risk of transformation. Over a lifetime, most patients with indolent lymphoma will not develop a transformed lymphoma.
Learn More
To learn more about transformed lymphomas, download the Transformed Lymphomas Fact Sheet. Want to talk to someone? For answers to lymphoma-related questions and resources, contact our Helpline at (800) 500-9976 or helpline@lymphoma.org.
Additional Resources
To learn more about transformed lymphomas, download the Transformed Lymphomas Fact Sheet.
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