Many hematologic disorders present minimal physical signs and symptoms in the early state. For example, chronic myelogenous leukemia may not manifest splenomegaly or any obvious physical signs, yet the laboratory report may demonstrate leukocytosis, eosinophilia, basophilia, and thrombocytosis. Although the anemic condition of a patient with a hemoglobin level of 7 gm/dl may be readily apparent to the clinician, a hemoglobin level of 10.5 gm/dl may be difficult to discern during a brief visit that is focused on another organ system. The same laboratory report, however, may contain valuable clues about unsuspected anemia related to mean corpuscular volume or morphology. Information from supporting chemistry studies often may be helpful in interpretation of the diagnosis. An elevated uric acid level, for example, may indicate hyperkinetic cytogenesis related to myeloproliferative or lymphoproliferative neoplastic disorders.

This monograph is designed to be useful to busy physicians who want to use basic hematologic studies in a cost-effective manner. Hematology is viewed in a problem-oriented way; the laboratory report is used as the problem generator.