Chronic Lymphocytic Leukemia

Excerpt

Chronic lymphocytic leukemia (CLL) or small lymphocytic lymphoma (SLL) is an indolent malignancy characterized by increased production of mature but dysfunctional B lymphocytes. CLL/SLL is defined as a monoclonal lymphoproliferative disease characterized by the proliferation and accumulation of morphologically mature but immunologically dysfunctional B-cell lymphocytes that are smudge cells, as noted on peripheral smear. The primary disease sites include peripheral blood, spleen, lymph nodes, and bone marrow. CLL and SLL are identical from a pathologic and immunophenotypic standpoint. Both CLL and SLL originate from B-cell lymphocytes but present with different manifestations depending on where the abnormal cells are found. Usually, the initial leukemic phase represents CLL, where the cells are present in the blood. This eventually progresses to the lymphoma phase, representing SLL, where the cells are found in the lymph nodes. The term SLL is commonly used to represent the lymphoproliferative process limited to the lymph nodes.