Which laboratory findings are associated with chronic lymphocytic leukemia (CLL)?

Chronic lymphocytic leukemia (CLL) is characterized primarily by an elevated white blood cell count, particularly lymphocytes. In this condition, leukocytosis is noted, often with white blood cell counts exceeding 50,000 cells per microliter. This finding is a hallmark of CLL and reflects the accumulation of mature but functionally impaired lymphocytes in the bloodstream, which can lead to various clinical complications.

Leukocytosis is accompanied by the presence of a predominance of small, mature lymphocytes on the blood smear, which can sometimes make the diagnosis of CLL evident. The chronic nature of the disease usually leads to these high leukocyte counts, which may be a few thousand or significantly higher, exceeding 50,000 in many cases.

In contrast, while alternatives may mention conditions like pancytopenia or neutropenia, these are not characteristic of CLL. In fact, pancytopenia is more related to bone marrow suppression or infiltration, not typically seen in isolated CLL. Neutropenia may occur in some patients due to the disease or its treatment but is not a defining feature of CLL at diagnosis. Increased platelets do not correlate with CLL, as thrombocytopenia or normal platelet