An intracavitary right ventricular mass: a diagnostic dilemma—a case report

Intracardiac masses are a diagnostic challenge in cardiology because thrombus and malignancy may demonstrate similar imaging features on initial evaluation.

An elderly male admitted for sepsis was incidentally found to have a right ventricular outflow tract mass initially presumed to be thrombus, and anticoagulation was initiated. Follow-up imaging demonstrated interval enlargement despite therapy, prompting further evaluation. Transesophageal echocardiography and cardiac magnetic resonance raised concern for malignancy, and biopsy confirmed poorly differentiated non–small cell lung carcinoma with cardiac metastasis. Given advanced disease and poor functional status, disease-directed therapy was deferred, and hospice care was pursued.

Cardiac metastases are more common than primary cardiac tumours and occur in up to 9%–14% of patients with metastatic cancer, with lung cancer representing the most frequent primary source. Prior literature emphasizes multimodal imaging when presumed thrombus fails to respond to anticoagulation.

Interval growth of an intracardiac mass despite anticoagulation should prompt diagnostic reassessment and advanced cardiac imaging.