[Diagnostic workup in front of an hypereosinophilia in 2020].

The discovery of eosinophilia above 1.5 G/L should not be considered innocuous, requiring monitoring for etiology and possible secondary organ damage. Among these, cardiac localization is the most worrying, sometimes indolent, to be systematically sought by ultrasound and magnetic resonance. The potential etiologies are very numerous, mostly reactive and corticosensitive, much more rarely clonal in relation to a malignant hemopathy usually chronic and myeloid, sometimes sensitive to tyrosine kinase inhibitors.