A predisposition to bacterial, viral, and fungal infection occurs in late disease because of hypogammaglobulinemia and granulocytopenia. In an asymptomatic patient, CLL may be diagnosed from abnormal blood counts. Otherwise, CLL should be suspected in a patient with insidious onset of the nonspecific features mentioned above who has generalized lymphadenopathy. CBC and bone marrow aspiration confirm diagnosis. Reactive lymphocytosis associated with viral infections can be differentiated by the clinical picture and the presence of atypical lymphocytes on blood smear.
Differential diagnosis is simplified by immunophenotyping.
Lymphocytic lymphomas with a leukemic phase are associated with circulating cells that are larger than those in CLL with distinctive notched nuclei. Clinical staging is useful for prognosis and treatment. The median survival of patients with B-cell CLL or its complications is about 10 yr. A patient in stage 0 to II at diagnosis may survive for 5 to 20 yr without treatment. A patient in stage III or IV is more likely to die within 3 to 4 yr of diagnosis.