A tricky and rare cause of pulmonary eosinophilia: myeloid/lymphoid neoplasm with eosinophilia and rearrangement of PDGFRA.

Correlation with clinical history, laboratory tests and imaging studies is essential to achieve the correct diagnosis when facing with eosinophilic lung infiltrates. A prolonged eosinophilia can cause life-threatening organ damage. Identification of PDGFRA rearrangement, as in the present case, is particularly critical given the sensitivity and excellent response to imatinib, which has completely changed the natural history of this neoplasm.