Hodgkin Variant Richter's Transformation in the Absence of Classical Risk Factors: A Rare Case With Spinal Manifestation.

Richter's transformation (RT) is a feared and not completely understood complication of chronic lymphocytic leukemia or small lymphocytic lymphoma (CLL/SLL). While most cases involve transformation to diffuse large B-cell lymphoma (DLBCL), CLL may, albeit rarely, progress to Hodgkin lymphoma (HL).  We report the case of a 74-year-old woman initially diagnosed with CLL/SLL who progressed to a rare form of HL subtype affecting the spinal cord. After receiving six cycles of brentuximab+doxorubicin, vinblastine, and dacarbazine (A+AVD) therapy at our Department of Hematology (University of Debrecen), the patient achieved complete metabolic remission (CMR) and remains in good condition. HL-RT in CLL is relatively rare and generally associated with poorer outcomes, though it is typically more favorable than DLBCL-RT. In this case report, we highlight not only an uncommon anatomical location of HL-RT but also the absence of typical predisposing factors, such as a TP53 mutation, unmutated immunoglobulin heavy chain (IGHV) status, or a lack of 13q deletion.