Richter syndrome, also termed Richter transformation, is a rare complication in which chronic lymphocytic leukemia (CLL) transforms into an aggressive lymphoma, most commonly diffuse large B-cell lymphoma. Transformation to Hodgkin lymphoma occurs in a subset of cases. Precise prevalence estimates are not well established.

Symptoms reflect the resulting aggressive lymphoma and may include rapidly enlarging lymph nodes, fever, unintended weight loss, and night sweats. Clinical presentation and severity vary among affected individuals depending on disease extent and lymphoma subtype.

Richter syndrome arises as an acquired transformation of CLL. Molecular studies indicate that in approximately half of cases the resulting lymphoma is clonally related to the underlying CLL; in other cases it represents a separate, unrelated neoplasm. The condition is not caused by an inherited genetic change.

Evaluation typically involves biopsy of an enlarging lymph node or mass for histopathologic confirmation of the lymphoma subtype. Pathologic assessment may distinguish clonally related from unrelated transformation. Imaging and bone marrow assessment contribute to staging.

Treatment planning depends on the lymphoma subtype, disease extent, prior CLL treatment history, and overall health. Management involves a multidisciplinary oncology team. Treatment approaches may include systemic therapies and supportive care. Treatment goals are individualized and may focus on disease control or symptom management.

Outcomes depend on the lymphoma subtype, the clonal relationship to underlying CLL, prior treatment history, and response to treatment. Prognosis varies substantially among affected individuals.

Richter syndrome is an active area of clinical investigation. Numerous certified active trial records are present, encompassing Phase 1, 2, and 3 studies. Drug therapy, biologic therapy, and investigational approaches are represented. Information on current trials is available through ClinicalTrials.gov.