Transformed Lymphoma

A transformed lymphoma is a lymphoma that was initially diagnosed as indolent (slow-growing) but has transformed into an aggressive (fast-growing) disease.

What causes an indolent disease to suddenly transform into an aggressive one? Added genetic changes to the tumor that occur organically can sometimes put the disease into overdrive, leading to a more aggressive disease.

This doesn't mean that a person whose disease has transformed will only have aggressive cancer cells; rather, that person's tumor will most likely include both indolent and aggressive cancer cells.

For this reason, treatment approaches will focus on the aggressive cells since they present a greater threat to the patient's health than the indolent ones.

Common Transformations

When transformation does occur, it will most commonly be among the following:

• Follicular lymphoma into diffuse large B-cell lymphoma
• Marginal zone lymphoma into diffuse large B-cell lymphoma
• Chronic lymphocytic leukemia into diffuse large B-cell lymphoma (Richter syndrome)
• Mantle cell lymphoma into blastoid mantle cell lymphoma

Risk of Transformed Lymphoma

What is the risk that a person with follicular lymphoma will have their disease transform into a more aggressive subtype? The risk, according to the Lymphoma Research Foundation, is considerably low: in a patient with indolent lymphoma, the overall risk is between one and three percent per year, with an overall lifetime risk of about 20 percent. Risk goes up each year until ten years, after which time, says the LRF, transformations are rare.

Derived largely from the Lymphoma Research Foundation's Fact Sheet on Transformed Lymphomas (opens as PDF)