Failure to suspect and diagnose thalassemic syndromes. Interpretation of RBC indices by the nonhematologist.

A three-year review of the medical records of 76 patients with apparent thalassemic syndromes (mean corpuscular volume, greater than 75 cu micron; RBC count, greater than 5 X 10(6)/cu mm) was performed to assess overall physician response to this information at a midwestern teaching institution. Abnormal indices were recognized in only 50% of the cases; in only 32% of cases was a thalassemic syndrome considered in the differential diagnosis. Residents in internal medicine failed to recognize microcytic indices and to consider thalassemic syndromes 42% and 59% of the time, respectively. Even though hemoglobin electrophoresis was performed in 25 patients, in only 15 (56%) of the 25 cases was beta-thalassemia proved or alpha-thalassemia presumptively diagnosed. In 17% of all cases, the patients were treated with iron without diagnostic findings on iron studies and/or in spite of data suggesting a thalassemic syndrome. The RBC indices are an underused portion of the complete blood cell count, and readily apparent thalassemic syndromes are often not considered.