Disseminated Nocardiosis With Perimyocardial Involvement

BACKGROUND: Nocardia pseudobrasiliensis causes opportunistic infection in immunocompromised hosts. Cardiac involvement is rare and may mimic malignancy or inflammatory disease. CASE SUMMARY: A 44-year-old woman with prior liver and kidney transplantation on immunosuppressants presented with pleuritic chest pain, cough, and subcutaneous nodules. Electrocardiogram showed diffuse ST-segment elevation and PR depression. Cardiac magnetic-resonance imaging revealed a heterogeneously enhancing left ventricular apical and anterior septal mass with extension into the right ventricle, along with pericardial thickening, and chest computed tomography demonstrated cavitary pulmonary nodules and a periscapular abscess. Aspiration of the periscapular abscess confirmed disseminated nocardiosis. She was treated with intravenous imipenem and trimethoprim-sulfamethoxazole with a steroid taper, resulting in clinical and radiographic improvement. DISCUSSION: This case illustrates a rare infectious cause of a myocardial mass and perimyocarditis identified through multimodality imaging, highlighting the importance of maintaining a broad differential diagnosis in transplant recipients presenting with infectious symptoms. TAKE-HOME MESSAGE: Nocardiosis and infection with other atypical organisms should be considered in immunosuppressed patients with cardiac masses to elucidate etiology early and target antimicrobial therapy to improve patient outcomes.