Differential Diagnosis of the Hemoglobinopathies

The imaging changes in sickle cell disease and thalassemia are readily recognized by the radiologist; the major problem in differential diagnosis is to exclude or distinguish concomitant bone infection in sicklers. Occasionally, aseptic necrosis of a hip or another joint seen in adult sicklers may be mistaken for osteochondritis (e.g., Legg-Perthes disease) or other etiology of avascular necrosis. The generalized osteopenia of sicklemia may be underestimated in patients who are undernourished; the cardiac and other changes may be blamed on anemia from malnutrition and parasites. However, the visceral changes in sickle cell disease are seldom apparent unless there are associated and more easily recognizable bone abnormalities. In thalassemia, the underlying cause of the enlargement of the liver and spleen and the cardiac hypertrophy may be missed, and the illness diagnosed as heart failure. The absence of any organic cardiac disease, the severity of the anemia, and the associated skeletal changes should guide the differential diagnosis towards the hemoglobin defects.