Chronic lymphocytic leukemia is a neoplatic disease
Pathophysiology
1) chronic lymphocytic leukemia is a neoplastic disorder with clonal proliferation of lymphocytes
2) 95% of cases are B cell in origin
3) primary site of involvement is the bone marrow (eventually bone marrow becomes completely replaced) with release into bloodstream of neoplastic lymphocytes
4) spleen, liver, and lymph nodes may become enlarged
5) 10 % of patients convert to prolymphocytic leukemia (most with more aggressive course)
6) 5% of patients with chronic lymphocytic leukemia convert to Richter’s syndrome
Signs and Symptoms of Chronic Lymphocytic Leukemia
1) can be very indolent with very few symptoms for years
2) splenomegaly is most striking physical finding of chronic lymphocytic leukemia
3) lymphadenopathy
4) recurrent infections (especially bacterial but can also be viral and fungal)
5) development of autoimmune hemolytic anemia
6) bleeding episodes and epistaxis
7) Richter’s syndrome – fever, abdominal pain, progressive lymphadenopathy, and hepatomegaly
Characteristic Test Findings
Laboratory
1) chronic lymphocytic leukemia (CLL) has significant increase in lymphocytes (both B and T cells)
2) anemia
3) granulocytopenia
4) thrombocytopenia (decreased platelets)
5) positive Coombs test (20%)
Histology/Gross Pathology
1) “smudge cell” on peripheral smear (ruptured cell membrane is characteristic)
2) diffuse effacement of normal lymph node with small lymphocytes
Associated Conditions
Increased incidence in
1) trisomy 12
2) translocations of chromosomes 11 and 14
3) deletions and inversions of chromosome 14
Increased incidence of
1) melanoma
2) soft tissue sarcoma
3) lung tumors
4) plasma cell tumors
Biochemistry
marked by hypogammaglobulinemia causing recurrent infections
Inheritance/Epidemiology
1) most common form of leukemia in Western nations
2) 13,000 new cases in USA each year
3) male to female, 2:1
4) occurs equally in blacks and whites
5) age of onset is typically 60-70 years
Tips for USMLE
1) not associated with radiation exposure, drug exposure, chemicals, or oncogenes
2) diagnosis requires bone marrow to be > 40% lymphocytes and peripheral blood to be > 5,000/microL
3) if question mentions smudge cells, think CLL
4) Richter’s syndrome is a large cell immunoblastic lymphoma
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