L4a

	Chronic lymphocytic leukemia B-cell type*******	Hairy cell
Definition	Neoplastic proliferation of small, immunologically incompetent B lymphocytes with unique immunophenotypic features; biologically identical to small lymphocytic lymphoma, but shows greater bone marrow and peripheral blood involvement at presentation	“Hairy” cells infiltrate mainly bone marrow and spleen; usually with only a small number of leukemic cells in peripheral blood.
Clinical	• Older patients (usually >40 years of age) • Insidious onset, often discovered as incidental finding  on CBC; eventual anemia, thrombocytopenia, splenomegaly, and/or lymphadenopathy	Pancytopenia + splenomegaly
Peripheral blood	Increase in small, mature lymphocytes	Small number hairy cells in blood
BM	Infiltration with similar lymphocytes	Hairy cells infiltrate BM/spleen
Immunophenotyoe	B lymphocytes with expression of CD5 and CD23	Leukemic cells exhibit - - Tartrate-resistent acid phosphatase (TRAP) - Unique immunophenotype “trap the hairy animal”
prognostic	Certain cell markers (eg. CD38 or ZAP-70 expression) and genetic abnormalities associated with more aggressive clinical course	Easily Rx – long survival
transformation	- Prolymphocytic transformation  15 - 30% - Large cell lymphoma (“Richter’s”) 5 - 10% - Acute leukemia very rare

·         Peripheral smear: What do you see? Increase in small, mature lymphocytes + Smudge cells

·        

       A positive CD5+ stain is associated with which two forms of lymphoid cancer?

o   Mantle, CLL

·         What do the cell markers represent?

o  CD5: mantle, CLL

o   CD23: B cell activation/growth (dendritic cell marker); mantle (CD23-)

o   CD38, ZAP 70 are associated with a more aggressive course

·         How do you know the cells are monoclonal in nature?

• expression of surface immunoglobulin of only one light chain class (“light chain restriction”)

·       5-10% of patients develop an aggressive large B cell lymphoma: what is this transformation called? Richter

·         Why is the patient anemic?

o   IgG à auto- antibody hemolytic anemia

o   Marrow overgrown with leukemic cells --> decrease in RBC production