Leukemia II: Chronic Lymphocytic Leukemia Overview

Leukemia-II

• Overview of chronic leukemia

• Chronic lymphocytic leukemia (CLL)

  • Definition: Monoclonal disorder with progressive accumulation of functionally incompetent mature B lymphocytes.
  • Accumulation sites: Bone marrow, blood, liver, spleen, and lymph nodes.
  • Epidemiology: Median age at diagnosis is 60 years; 2:1 male predominance.
  • Clinical features: Generalized lymphadenopathy (enlarged lymph nodes), hepatosplenomegaly (enlarged liver and spleen) in 50-60% of cases, anemia, thrombocytopenia (low platelet count) leading to bruising/purpura, and hypogammaglobulinemia (increased risk of infections).
  • Diagnosis criteria (NCCN): Peripheral blood lymphocyte count of ≥5000/µL (normal 1000-3000/µL), small mature lymphocytes with high nucleus-to-cytoplasm ratio (N/C), round to oval nuclei with clumped chromatin, clonality confirmed by flow cytometry, and immunophenotyping showing CD19, CD20, CD23.
  • Laboratory findings: Elevated WBCs (>100,000/dL), predominantly lymphocytes, anemia, and thrombocytopenia. Bone marrow shows mature B lymphocytic replacement. Immunophenotyping shows expression of CD19, CD20, CD23, and CD5.
  • Prognosis: Dependent on the stage of the disease; two staging systems are used (Binet and Rai-Sawitsky).

• Chronic Myeloid Leukemia (CML)

  • Definition: Neoplastic proliferation of the granulocytic cell line, without loss of differentiation capacity, characterized by the Philadelphia chromosome.
  • Epidemiology: Primarily a disease of adults, but can occur in children and adolescents; peak incidence in the fifth to sixth decades of life.
  • Stages: Chronic stage (85% of patients), accelerated stage, and acute blastic crisis.
  • Chronic stage clinical features: Anemia, low-grade fever, fatigue, weight loss, loss of energy, night sweats, abdominal fullness (due to splenomegaly), left upper quadrant pain (from spleen infarction), hepatomegaly, easy bruising/spontaneous bleeding, and gout/renal impairment due to hyperuricemia (high uric acid).
  • Laboratory findings (chronic stage): Markedly elevated WBCs (>100,000/dL), basophilia (important finding) and eosinophilia, anemia, thrombocytosis. Bone marrow hypercellular with increased myeloid cells, basophils, eosinophils, and megakaryocytes.
  • Cytogenetic analysis: Necessary to detect the Philadelphia chromosome (reciprocal translocation between chromosome 9 and 22, t(9;22)(q34;q11)), leading to shortened chromosome 22.
  • Prognosis: Slow progression; median survival roughly three years without treatment.

Case Studies

• Case Study 1: 72-year-old man with fatigue, weight loss, and lymphadenopathy, diagnosed with Chronic lymphocytic leukemia (CLL).
• Case Study 2: 64-year-old woman with abdominal discomfort, fatigue, and weight loss, diagnosed with Chronic myeloid leukemia (CML).