CLL as a cause of a persistent increase in absolute numbers of lymphocytes

• CLL is the most indolent of the leukemias

• 25% of leukemias, seen in people > 50 YOA, males 2X more

• Most are of B cell type and express small amounts of IgM or IgD with restriction to  or  light chains (they are monoclonal)

• They are mature B cells and as such will express pan-B cell Ags like CD19 and CD20 but not the early-B cell Ags like CD10 (common ALL Ag, CALLA) or TdT

• CD5 (a T-cell Ag) is expressed on some B cells

• T cell CLL is rare (<>

• Associated with bcl-1 and bcl-2 mutations (sometimes)

• Nonspecific C/S; generalized lymphadenopathy and hepatosplenomegaly in 50-60% of cases

• Evan’s syndrome

  • Formation of Abs against RBCs and platelets in 10-15% of CLL patients

  • Get an autoimmune hemolytic anemia and/or thrombocytopenia

• Survival depends on how long disease went undiagnosed; worst prognosis with anemia or thrombocytopenia

• Transformation to acute leukemia with blast crisis rare; more common to progress to prolymphocytic leukemia (more aggressive than CLL but not as aggressive as an acute leukemia)

Category: Medical Subject Notes , Pathology Notes