Nearly all patients with chronic lymphocytic leukemia are men older than age 50. According to the American Cancer Society, chronic lymphocytic leukemia accounts for almost one-third of new leukemia cases annually.
Although the cause of chronic lymphocytic leukemia is unknown, researchers suspect hereditary factors (higher incidence has been recorded within families), still-undefined chromosome abnormalities, and certain immunologic defects (such as ataxia-telangiectasia or acquired agammaglobulinemia). The disease doesn’t seem to be associated with radiation exposure.
Signs and symptoms
Chronic lymphocytic leukemia is the most benign and the most slowly progressive form of leukemia. Signs and symptoms derive from the infiltration of leukemic cells in bone marrow, lymphoid tissue, and organ systems.
In early stages, patients usually complain of fatigue, malaise, fever, and nodal enlargement. They’re particularly susceptible to infection, which may be fatal.
In advanced stages, patients may experience severe fatigue and weight loss, with liver or spleen enlargement, bone tenderness, and edema from lymph node obstruction. Pulmonary infiltrates may appear when lung parenchyma is involved. Skin infiltrations, manifested by macular to nodular eruptions, occur in about one-half of the cases of chronic lymphocytic leukemia.
As the disease progresses, bone marrow involvement may lead to anemia, pallor, weakness, dyspnea, tachycardia, palpitations, bleeding, or infection. Opportunistic fungal, viral, and bacterial infections commonly occur in late stages and result in fatal septicemia.
Typically, chronic lymphocytic leukemia is an incidental finding during a routine blood test that reveals numerous abnormal lymphocytes. In early stages, the white blood cell (WBC) count is mildly but persistently elevated. Granulocytopenia is the rule, but the WBC count climbs as the disease progresses.
Blood studies also show a hemoglobin level below 11 g, hypogammaglobulinemia, and depressed serum globulin levels. Other common findings include neutropenia (less than 1,500/µl), lymphocytosis (more than 10,000/µl), and thrombocytopenia (less than 150,000/µl). Bone marrow aspiration and biopsy show lymphocytic invasion.
Systemic chemotherapy includes an alkylating drug, usually chlorambucil or cyclophosphamide, and sometimes a steroid (prednisone) when autoimmune hemolytic anemia or thrombocytopenia occurs.
When chronic lymphocytic leukemia causes obstruction or organ impairment or enlargement, local radiation treatment can be used to reduce organ size. Allopurinol can be given to prevent hyperuricemia, a relatively uncommon finding.