To describe a rare case of myeloid variant hypereosinophilic syndrome as an etiology for stroke in the young, a complication not previous reported in the literature.

Myeloid variant of hypereosinophilic syndrome is a rare myelodysplastic syndrome secondary to clonal proliferation of eosinophils. This leads to a hypercoagulability, and in this case a multifocal stroke with characteristic pattern of fine peppering in watershed zones seen on DWI complicated by extra-cerebral manifestations including myocarditis and splenic infarcts.

A 29 year old male with past medical history of asthma is admitted to the hospital for chest pain with troponin elevations and hypereosinophilia. Subsequent LHC and stress test negative, in retrospect thought to represent eosinophilic myocarditis. During hospitalization patient developed acute onset short term memory loss leading to MRI revealing bilateral fine embolic watershed strokes. Subsequent workup revealing splenomegaly with wedge infarct. Patient started on high dose IV steroids with improvement in hypereosinophilia, eventually requiring inpatient mepolizumab (an IL-5 inhibitor utilized for hypereosinophilic syndrome) before being transitioned to maintenance oral prednisone. Subsequent workup with bone marrow biopsy reveals myelodysplastic process with subsequent FISH revealing FIP1L::PDGFRAx2 gene rearrangement. Patient discharged on aspirin, atorvastatin and oral prednisone with resolution of memory impairment. Following with hematology outpatient they were transitioned to Imatinib (a tyrosine kinase inhibitor) with oral prednisone taper planned for long term targeted therapy.

This case describes a rare complication of myeloid variant hypereosinophilic syndrome in the young not previously described in the literature. This remains an important treatable cause of hypercoagulability and an easily missed differential for stroke in the young, with more research being necessary for further elucidation of this rare disease state.