MedGen

Increase in the number or proportion of lymphocytes in the blood. [from HPO]

A monoclonal expansion of B-lymphocytes with or without the characteristic immunophenotype of chronic lymphocytic leukemia. It precedes virtually all cases of chronic lymphocytic leukemia/small lymphocytic lymphoma. [from NCI]

Chronic lymphocytic leukemia (CLL) is a common neoplasia of B lymphocytes in which these cells progressively accumulate in the bone marrow, blood, and lymphoid tissues. The clinical evolution of the disorder is heterogeneous, with some patients having indolent disease and others having aggressive disease and short survival (summary by Quesada et al., 2012). Genetic Heterogeneity of Susceptibility to Chronic Lymphocytic Leukemia Susceptibility loci have been mapped to chromosomes 11p11 (CLLS1; 609630) and 13q14 (CLLS2; 109543) by genomewide linkage analysis and translocation studies, respectively. Susceptibility mapping to chromosome 9q34 (CLLS3; 612557) is associated with downregulation of the DAPK1 gene (600831). Genomewide association studies have identified susceptibility loci on chromosomes 6p25.3 (CLLS4; 612558) and 11q24.1 (CLLS5; 612559). [from OMIM]

A malignant lymphocytic neoplasm of B-cell or T-cell lineage involving primarily the bone marrow and the peripheral blood. This category includes precursor or acute lymphoblastic leukemias and chronic leukemias. [from HPO]