Abstract
BACKGROUND: Intracardiac lesions in immunocompromised patients with negative blood culture pose a diagnostic challenge, particularly when both thrombus and infective endocarditis are possible etiologies. CASE SUMMARY: A young woman with a history of lung transplantation on immunosuppression and thrombophilia was found to have new hypermetabolic, mobile lesions involving the interventricular septum. Blood cultures were negative, and owing to prohibitive surgical risk, she was managed conservatively with antibiotics, with an excellent response. DISCUSSION: This case highlights the diagnostic complexity and the role of multimodality imaging associated with defining the etiology and treatment plan for intracardiac lesions in a patient with multiple medical comorbidities. TAKE-HOME MESSAGE: Culture-negative endocarditis requires a high index of suspicion in immunocompromised patients with thrombotic risk factors and inconclusive microbiological and echocardiographic findings.