 Chronic lymphocytic leukemia and small B-cell lymphocytic lymphoma represent different manifestations of the same disease. CLLSLL hereafter denoted by CLL is a clonal disorder of small B lymphocytes expressing a characteristic morphology and immunophenotype. The B cells express CD19, dim CD 20, dim CD 5, CD 23, CD 43, CD 79a, and weakly express surface immunoglobin. CLL can present asymptomatically in 25 of patients when diagnosed on a complete blood count. It also can present with diffuse painless lymphadenopathy and, in a smaller number of patients, B symptoms. 