A Case-based Review of Chronic Lymphocytic Leukemia

INTRODUCTION The diagnosis and treatment of chronic lymphocytic leukemia (CLL) has undergone a profound expansion in scientific and medical understanding in the last decade. Commonly held beliefs of signs and symptoms at time of diagnosis, required laboratory testing, and choices of therapy have all changed.

A 34-year old male medical laboratory science (MLS) student tested his own blood as part of an exercise in the use of an automated instrument. His initial CBC is seen in Table 1. Figure 1 shows an oil immersion magnification view of the lymphocytes on his peripheral blood smear. He agreed to see his primary care physician the next day. The repeat CBC was ordered the next day and the results were essentially unchanged. When questioned the physician said that a viral infection could be the cause. The patient later remarked that he had no obvious signs and symptoms although focused questioning brought out a state of fatigue, night sweats, and a mild viral infection that took over 6 weeks to get over. As is typical with many newly diagnosed patients with CLL, he did not have an anemia or thrombocytopenia. Please see Figure 2.

Family history includes a father who died from a lymphoproliferative (non-Hodgkin lymphoma) disorder in the 1980s. Some studies have suggested that there may be a familial risk of leukemia in relatives of lymphoproliferative disorder patients.¹

At its base definition, CLL is a monoclonal production of greater than 5x10⁹ B lymphocytes/L mature-looking but dysfunctional lymphocytes in the peripheral blood.² While small…

ABBREVIATIONS: CLL – chronic lymphocytic leukemia, IgVH – immunoglobulin heavy chain mutation, ZAP 70 - zeta chain associated protein kinase 70, FISH – fluorescent in situ hybridization, ATM – Ataxia telangiectasia mutated