# Loeffler endocarditis revealing chronic eosinophilic leukaemia with FIP1L1-PDGFRA rearrangement: a case report

## TL;DR

A case of chronic eosinophilic leukemia with heart complications is reported, emphasizing the importance of early diagnosis and treatment.

## Contribution

This case report highlights Loeffler endocarditis as a potential initial sign of chronic eosinophilic leukemia with FIP1L1-PDGFRA rearrangement.

## Key findings

- Loeffler endocarditis can be the sole presenting feature of chronic eosinophilic leukemia.
- Timely diagnosis and treatment led to hematological remission and resolution of cardiac thrombi.
- Collaboration between cardiologists and internists is essential for optimal patient outcomes.

## Abstract

Hypereosinophilic syndrome (HES) is an infrequent multisystemic disorder with a serious prognosis, defined by persistent marked eosinophilia (>1500 eosinophils/mm3) associated with organ damage from eosinophil-mediated cytotoxicity. Cardiac involvement is a significant and unpredictable complication of hypereosinophilic syndrome, particularly prevalent in patients carrying the FIP1L1-PDGFRA fusion.

Reported is a case of chronic eosinophilic leukaemia (CEL) with a FIP1L1-PDGFRA rearrangement, diagnosed in a 31-year-old patient presenting with Loeffler endocarditis. Intracardiac thrombi and embolic cerebral infarctions complicated the case. The patient demonstrated haematological remission following chemotherapy, and anticoagulation treatment led to thrombi resolution.

This case highlights that Loeffler endocarditis can present as the primary and sole manifestation of chronic eosinophilic leukaemia. Effective collaboration between cardiologists and internists is crucial for timely diagnosis and comprehensive management, ultimately resulting in enhanced outcomes.