An awesome discussion from the @CPSolvers and Drs. Gandhi and Bressman! Here are some thoughts about the pivot point of the case... #SpoilerAlert
Drs. Gotlib and Reiter put an an excellent review discussing myeloid neoplasms with hypereosinophilia (ashpublications.org/blood/article-…), these are some of the salient points for all IM folks to take away
The first is knowing that the terms hypereosinophilia and hypereosinophilic syndrome (HES) carry specific meaning! HES meets the definition for hypereosinophilia + there is organ damage 2/2 hypereosinophilia 
The second is having a systematic way to work up hypereosinophilia! The @CPSolvers have a wonderful schema (bit.ly/3auyCU5) , here's a figure with a heme-tilted workup. It's important to know what cytogenetic/molecular studies were actually sent from a bone marrow biopsy
The third and final takeaway is that these genetic aberrations matter not just for diagnostic purposes, but also for treatment purposes! The below figures highlight characteristic BM findings and treatment option considerations
