Wallach's Interpretation of Diagnostic Tests: Pathways to Arriving at a Clinical Diagnosis (324 page)

   Who Should Be Suspected?

Agranulocytosis should be suspected in anyone started recently or restarted on any drug, who suddenly develops fever, chills, and signs of infection. Sore throat is a common presenting symptom. Patients may develop overwhelming sepsis.

   Laboratory Findings

   CBC: normal Hb and platelets (except under special circumstances, such as postchemotherapy); absent or extremely decreased neutrophils and bands. The granulocytes may show pyknosis or vacuolization. Normal lymphocytes and monocytes (but relative lymphocytosis and monocytosis).

   Bone marrow shows an absence of cells in the granulocytic series but normal erythroid and megakaryocytic series.

   ESR is increased.

   Other laboratory findings reflect the infection.

   Hb, RBC count and morphology, platelet count, and coagulation tests are normal.

LYMPHOCYTOSIS

   Definition

Lymphocytosis is defined as an absolute lymphocyte count >3,400/μL (or >43%) in adults, >7,200 in adolescents, and >9,000 in young children and infants. Spurious lymphocytosis: neutropenia with relative lymphocytosis, but normal absolute lymphocyte count.

   Primary (Clonal) Lymphocytosis

   Chronic lymphocytic leukemia (CLL)

   Monoclonal B-cell lymphocytosis (>4,000 but <5,000 clonal lymphocytes)

   Acute lymphocytic leukemia (ALL)

   Prolymphocytic leukemia