Late-Stage Löffler's Endocarditis Mimicking Cardiac Tumor: A Case Report

Area of Science:

• Cardiology
• Hematology
• Pathology

Background:

• Hypereosinophilic syndrome (HES) is a rare disorder characterized by persistent eosinophilia.
• Cardiac involvement in HES, known as Löffler's endocarditis, is a serious complication.
• Löffler's endocarditis can present insidiously or dramatically, often mimicking other cardiac pathologies.

Observation:

• A case of HES presented with a cardiac mass and abnormal electrocardiogram, initially suspected as a malignant cardiac tumor.
• Multimodality imaging suggested a tumor invading the papillary muscle, necessitating surgical intervention.
• Surgical pathology revealed thrombosis and myocardial damage due to eosinophilic infiltration, not malignancy.

Findings:

• The final diagnosis was late-stage Löffler's endocarditis, confirmed by pathological examination.
• Surgical resection of the cardiac mass and endomyocardial resection with mitral valve replacement were successfully performed.
• A combination of anticoagulation and corticosteroids proved effective in managing the condition.

Implications:

• This case underscores the diagnostic challenges posed by cardiac masses in HES.
• It highlights potential pitfalls in interpreting cardiac imaging for thrombus versus tumor.
• Considering Löffler's endocarditis in the differential diagnosis of cardiac masses is clinically significant for timely and appropriate management.