Sideroblastic Anemia
A 70-year-old woman with a history of ischemic heart disease was hospitalized because of generalized weakness, fatigue, and retrosternal chest pain on mild exertion. Her skin was pallid. Chest and heart evaluations were normal, and mild hepatosplenomegaly was discerned.
A 70-year-old woman with a history of ischemic heart disease was hospitalized because of generalized weakness, fatigue, and retrosternal chest pain on mild exertion. Her skin was pallid. Chest and heart evaluations were normal, and mild hepatosplenomegaly was discerned. The white blood cell count was 3,300/µL with a normal differential count; platelet count, 90,000/µL; hemoglobin, 9 g/dL; and serum ferritin, 120 ng/mL. Other serum chemistry results and chest film and ECG findings were normal. Ringed sideroblasts (cells with iron-laden mitochondria that have a perinuclear distribution) are evident in the iron-stained bone marrow aspirations, pictured here, and confirmed the diagnosis of sideroblastic anemia.
Sideroblastic anemias are a heterogeneous group of disorders characterized by iron deposits in the erythroblast mitochondria,1 write Drs Hesham Taha, Gamil Kostandy, Maged Ghaly, and David Dosik of New York Methodist Hospital in Brooklyn. Some cases of these anemias are hereditary or are associated with myelodysplasia, hematologic malignancies, and myeloproliferative disorders. A reversible form of sideroblastic anemia can be caused by alcohol, isoniazide, and chloramphenicol.2
Most cases are idiopathic and occur in middle-aged and older persons. Typically, patients are asymptomatic, and the disease is discovered during a routine examination. Older patients may complain of generalized weakness and chest pain, particularly if there is a history of ischemic heart disease. Pallor is common, and hepatosplenomegaly develops in 50% of the patients. Laboratory work-up reveals increased transferrin saturation and serum ferritin level. Symptomatic patients may be treated with packed red blood cell transfusions. Pyridoxine or high-dose androgens can be tried; most patients do not respond, however. Consider treatment for iron overload when the patient's serum ferritin level is 500 ng/mL or greater. This patient received periodic transfusions of packed red blood cells, and her symptoms improved markedly.
REFERENCES:1. Fitzsimons EJ, May A. The molecular basis of the sideroblastic anemias. Curr Opin Hematol. 1996;3:167-172.
2. Koc S, Harris JW. Sideroblastic anemias: variations on imprecision in diagnostic criteria; proposal for an extended classification of sideroblastic anemias. Am J Hematol. 1998;57:1-6.
