Richter's transformation (RT), also known as Richter's syndrome, is the conversion of chronic lymphocytic leukemia (CLL) or its variant, small lymphocytic lymphoma (SLL), into a new and more aggressively malignant disease.[1] CLL is the circulation of malignantB lymphocytes with or without the infiltration of these cells into lymphatic or other tissues while SLL is the infiltration of these malignant B lymphocytes into lymphatic and/or other tissues with little or no circulation of these cells in the blood.[2] CLL along with its SLL variant are grouped together in the term CLL/SLL.[1]
CLL/SLL is the most common adult leukemia in Western countries, accounting for 1.2% of the new cancers diagnosed each year in the United States. It usually occurs in older adults (median age at diagnosis 70) and follows an indolent course over many years.[11] About 1-10% of CLL/SLLs develop a Richter's transformation at a rate of 0.5–1% per year. In earlier studies, the transformed disease was reported to be far more aggressive than CLL/SLL with overall median survival times (i.e. times in which 50% of cases remain alive) between 1.1 and 16.3 months. Newer therapeutic regimens are improving the prognosis of DLBCL-RT and HL-RT.[12]
^ abTrimech M, Letourneau A, Missiaglia E, De Prijck B, Nagy-Hulliger M, Somja J, Vivario M, Gaulard P, Lambert F, Bisig B, de Leval L (June 2021). "Angioimmunoblastic T-Cell Lymphoma and Chronic Lymphocytic Leukemia/Small Lymphocytic Lymphoma: A Novel Form of Composite Lymphoma Potentially Mimicking Richter Syndrome". The American Journal of Surgical Pathology. 45 (6): 773–786. doi:10.1097/PAS.0000000000001646. hdl:2268/289883. PMID33739791. S2CID232301854.
^Travis LB, Curtis RE, Hankey BF, Fraumeni JF (September 1992). "Second cancers in patients with chronic lymphocytic leukemia". Journal of the National Cancer Institute. 84 (18): 1422–7. doi:10.1093/jnci/84.18.1422. PMID1512794.
^Soilleux EJ, Wotherspoon A, Eyre TA, Clifford R, Cabes M, Schuh AH (December 2016). "Diagnostic dilemmas of high-grade transformation (Richter's syndrome) of chronic lymphocytic leukaemia: results of the phase II National Cancer Research Institute CHOP-OR clinical trial specialist haemato-pathology central review". Histopathology. 69 (6): 1066–1076. doi:10.1111/his.13024. PMID27345622. S2CID205171057.