The CBC, white blood cell differential, and blood smear examination initially alert us to the possibility of a leukemia diagnosis in the laboratory. The laboratory professional will typically note elevated white counts, immature cells and cell morphologies, and possibly abnormal red cell or platelet counts. The white cell differential can give a clue as to whether the leukemia is acute or chronic and myeloid or lymphocytic.
Cell staging and differentiation between myeloid and lymphocytic cells are important first steps, as is determining whether the leukemia is acute or chronic.
Further laboratory samples will then be evaluated. These will include bone marrow biopsy and aspirations and, less commonly, cerebrospinal fluid or tissue samples. A pathologist typically evaluates bone marrow morphology; flow cytometry, cytogenetic analysis, and genetic studies will be performed for the definitive diagnosis.
