Low-count<unk>  is an indolent disorder that in virtually all individuals does not progress to a malignant phase. Overall survival in low count<unk>  does not differ from that found in age-matched healthy individuals.<unk> -MZ is an exception to this rule: this disorder generally presents with high<unk>  B-cell counts and regardless of the level of these counts may progress to a malignant phase at a greater than that found in other forms of<unk> . Depending on its phenotype (see above Table), high-count<unk>  progresses to CLL/SLL, mantel cell lymphoma, follicular lymphoma, splenic marginal zone lymphoma, or splenic lymphoma/leukemia unclassifiable at a rate of 1-2% per year whereas<unk> -MZ progresses to a marginal zone B-cell lymphoma, Waldenström's macroglobulinemia, or Hairy cell leukemia at a ~3% per year. Factors predisposing to this progression in CLL/SLL<unk>  include the expression of CD38 cell-surface glycoprotein on the<unk>  B-cells, deletion of the short arm of chromosome 17 in these cells, high serum levels of beta-2 macroglobulin, and circulating B cell levels >10x109/L. There is relatively little information on the features promoting the progression of atypical CLL/SLL<unk> , non-CLL/SLL<unk> , and<unk> -MZ to their respective lymphomas. Individuals with high-count<unk>  (studies based primarily on the CLL/SLL phenotype) are at an increased risk for developing: 1) cancers of the breast, lung, and gastrointestinal tract in up to 13% of all cases; 2) autoimmune hemolytic anemia and immune thrombocytopenic purpura; 3) unexplained kidney disease as manifested by chronic kidney disease and/or the nephrotic syndrome; and 4) serious infections. While earlier studies suggested that only very high-count<unk>  (i.e. >10x109 B-cells/L) was associated with a decrease in survival, more recent studies indicate that high-count<unk>  (i.e. (i.e. >0.5x109 B-cells/L) do show a shorter overall survival. In addition to having very high numbers of B-cells, high-count CLL/β2 macroglobulin is elevated have a shorten survival. However, the shortened survival times in high-count CLL/SLL<unk>  does not appear due to its progression to CLL/SLL. Rather, this shortened survival appears due to the disorders' susceptibility to serious infections, other types of cancers, immune cytopenias, and renal disease. Recommended treatments for patients with high-count<unk>  and<unk> -MZ include yearly follow-up evaluations to test for the malignant progression of their disorder and for the development of other forms of cancer, infections, immune cytopenias, and renal disease. It may also be beneficial to ensure that high-count MLB patients are up to date on vaccinations including those for influenza, pneumococcal pneumonia, and tetanus before they become more severely immunocompromised by the progression of their disorder. In all cases live vaccines should be avoided in these individuals.
Monoclonal B-cell lymphocytosis
Persistent polyclonal B-cell lymphocytosis
Abscess of thymus
Idiopathic CD4+ lymphocytopenia
Cutaneous lymphoid hyperplasia
Persistent generalized lymphadenopathy
Thymic hypoplasia
Lymphoid neoplasms with plasmablastic differentiation