[Systemic mastocytosis with eosinophilia]

A 67-year old female patient presented with marked eosinophilia in the peripheral blood. The patient had asymptomatic systemic mastocytosis which she had probably had for many years. At the time of diagnosis, the eosinophilia had already produced symptoms of cardiac insufficiency. The patient was treated with prednisone and hydroxyurea which reduced the eosinophil count. In spite of treatment cardiac symptoms progressed, the patient developed atrial flutter, and died in pulmonary oedema. The autopsy showed fibrotic changes in the heart as seen in the fibrotic end stage of Löeffler's endomyocardial disease. The possible reasons for eosinophilia in the patient are discussed.