Richter's transformation
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. CLL is the circulation of malignant B 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.