Silent Myocardial Infarction in Hypereosinophilic Syndrome Overlapped with JAK2-Mediated Essential Thrombocytosis: A Case Report

Abstract

A 61-year-old male with chronic cough, paraesthesia of the extremities, and sinusitis presented for acute worsening of symptoms despite initial treatment with antibiotics and prednisone. Emergency department evaluation revealed mild elevated troponin without ECG changes in absence of coronary symptoms, but markedly elevated eosinophil count and an abnormal chest CT. A nuclear stress test revealed basal and inferoseptal dyskinesis with fixed apical defect. Left heart catheterisation revealed multiple coronary stenosis requiring intervention. Further extensive work-up confirmed a diagnosis of hypereosinophilic syndrome complicated with respiratory, cardiac, gastroenterological, and neurological involvement. The patient was initially treated with a high dose of intravenous steroid and hydroxyurea. Flow cytometry revealed negative FIP1L1-PDGFRA gene rearrangement, but was positive for JAK2 V617F mutation and perinuclear antineutrophil cytoplasmic antibodies/cytoplasmic antineutrophil cytoplasmic antibodies, indicating possible overlap of eosinophilic granulomatosis with polyangiitis.