What is a hallmark symptom of Chronic Lymphocytic Leukemia (CLL)?

A hallmark symptom of Chronic Lymphocytic Leukemia (CLL) is lymphocytosis, which refers to an elevated level of lymphocytes in the blood. In CLL, this condition arises due to the uncontrolled proliferation of abnormal lymphocytes, specifically B-lymphocytes, leading to their accumulation in the blood, bone marrow, and lymphoid tissues. This characteristic lymphocytosis is often detected during routine blood tests, making it a defining feature of the disease.

Neutropenia, thrombocytopenia, and pancytopenia can occur in various hematological conditions, including other types of leukemias or during advanced stages of CLL, but they are not specific to CLL. These conditions may indicate a more severe disease state or complications related to the bone marrow’s production of blood cells, but they do not serve as the primary characteristic of classic CLL. In contrast, lymphocytosis effectively embodies the pathological process of CLL, distinguishing it from other hematological disorders.