Richter’s Transformation or Richter’s Syndrome (RS) is a rare complication of CLL characterized by the sudden transformation of the CLL into a significantly more aggressive form of large cell lymphoma.

Richter’s Transformation occurs in approximately 2-10% of all CLL patients during the course of their disease.

In most cases, the normally slow-growing or indolent CLL transforms into a common type of aggressive non-Hodgkin lymphoma (NHL) known as Diffuse Large B Cell Lymphoma (DLBCL).  Rarer cases transform into Hodgkin lymphoma (HL) and some types of T-cell lymphomas have also been reported.

Once the transformation happen, the lymphoma is treated with the standard therapies used for DLBCL or HL.