Review Question - QID 106090

The patient presents with clinical signs and pathological findings consistent with chronic lymphocytic leukemia. Diagnosis should be confirmed with flow cytometry.

Chronic lymphocytic leukemia is most commonly seen in older adults. Its onset is often insidious in comparison to the acute leukemias. Patients often present with painless lymphadenopathy. A peripheral blood smear reveals smudge cells, which are fragile abnormal cells that get crushed during slide preparation resulting in their classic appearance (Figure A). In flow cytometry, cells from peripheral blood are fed through an analyzer that detects surface markers or antigens. Chronic lymphocytic leukemia is caused by a neoplastic expansion of CD5 and CD20-positive B cells.

Maurer and Hallek discuss chronic lymphocytic leukemia. Chronic lymphocytic leukemia accounts for 30% of adult leukemias and 25% of non-Hodgkin's lymphomas. The mean age of diagnosis is 70 years and there is a predominance in men. Cervical lymphadenopathy and splenomegaly followed by general fatigue are the most common symptoms, but patients may also experience night sweats, fever, weight loss, and frequent infections. Common complications include autoimmune hemolytic anemia and immune thrombocytopenia.

Abramson and Melton discuss the basics of clinical assessment of leukocytosis. Primary bone marrow disorders should be suspected in patients who present with extremely elevated white blood cell counts or concurrent abnormalities in red blood cell or platelet counts. Weight loss, bleeding or bruising, liver, spleen or lymph node enlargement, and immunosuppression also increase suspicion for a marrow disorder. The most common bone marrow disorders can be grouped into acute leukemias, chronic leukemias and myeloproliferative disorders.

Figure A depicts a smudge cell, the characteristic finding on peripheral blood smear in chronic lymphocytic leukemia.

Incorrect Answers:
Answer 1: A bone marrow biopsy may be indicated in certain leukemias, but flow cytometry is sufficient in diagnosis of chronic lymphocytic leukemia and is a lot less painful for the patient.
Answer 2: CT of the head and neck may be useful for evaluation, but cannot confirm the diagnosis.
Answer 3: MRI of the head and neck is useful in neurological evaluation, but cannot confirm the diagnosis of CLL.
Answer 5: A heterophile antibody test would be useful in diagnosing mononucleosis, which could present similarly in a younger patient, but is unlikely in this elderly man.