chronic lymphocytic leukemia
Also written as: CLL — chronic lymphocytic leukemia
A malignancy characterized by the clonal proliferation and accumulation of mature-appearing B lymphocytes in blood, bone marrow, and lymphoid organs.
Full Definition
Chronic lymphocytic leukemia (CLL) is the most common leukemia in Western countries, primarily affecting older adults with a median age at diagnosis of 72 years. The disease is characterized by the progressive accumulation of monoclonal B lymphocytes that appear morphologically mature but are functionally defective. CLL typically follows an indolent course, though some patients experience rapid progression. Diagnosis requires demonstration of clonal B-cell lymphocytosis with characteristic immunophenotype. The disease is closely related to small lymphocytic lymphoma, differing primarily in the degree of lymphadenopathy versus peripheral blood involvement.
Usage
Usage note: Commonly abbreviated as CLL. Should not be confused with chronic myeloid leukemia (CML).
In Context
- "The patient's chronic lymphocytic leukemia was diagnosed incidentally during routine blood work." — Clinical case presentation
- "Immunophenotyping confirmed the diagnosis of chronic lymphocytic leukemia with typical CD19+/CD23+ expression." — Laboratory report