A 66-year-old male is referred for assessment of lymphocytosis. This has been stable for the past year with no associated lymphadenopathy, B symptoms, or infections.
- Is this patient at risk for leukostasis?
- What is the diagnostic test of choice for this condition?
- What hematologic autoimmune syndrome can be seen in such patients?
Click for answer:
Diagnosis: chronic lymphocytic leukemia (CLL)
CBC Clues:
(1) Lymphocytosis (2) Smudge cells
Q1: Is this patient at risk for leukostasis?
No
Q2: What is the diagnostic test of choice for this condition?
Flow cytometry
Q3: What hematologic autoimmune syndrome can be seen in such patients?
Autoimmune hemolytic anemia
Rai Staging
• Enlarged lymph nodes
• Enlarged spleen
• Enlarged liver
• Anemia (< 110)
• Thrombocytopenia
(100, 000)
CLL is caused by expansion of a monoclonal population of mature B-cells. Many patients can be asymptomatic for their whole lives while others can present with cytopenias, lymph node enlargement, symptomatic splenomegaly, or B-symptoms. The Rai classification system (see Box for simplified criteria) is commonly used to stage CLL and predict risk of progression. There are multiple lines of treatment available for symptomatic individuals, including small-molecule inhibitors and chemotherapy.
Leukostasis is a phenomenon whereby leukemic tumor cells can increased blood viscosity, leading to vascular occlusion and end-organ damage. However, this is not typically seen in cases of chronic leukemia, including CLL, because the cells are smaller and more mature than blast cells.
CBC Pearls
• AIHA is present in up to 10% of CLL patients
• Flow cytometry is the diagnostic test for CLL
The diagnostic test of choice for CLL is flow cytometry in order to characterize the monoclonal B cell population. Autoimmune hemolytic anemia can be seen in up to 10% of CLL patients and should be ruled out if there is concomitant anemia. Smudge cells are commonly seen on a peripheral blood smear and represent fragile, mature lymphocytes that are “smudged” during slide preparation. They can be seen in other disorders and are not diagnostic of CLL.