An unprecedented case report of primary cardiac lymphoma exclusive to left ventricle: a diagnostic and therapeutic challenge.

Introduction: Primary cardiac lymphoma accounts for <2% of all primary cardiac tumours. It is uncommon in immunocompetent patients, often fatal and diagnosed at autopsy. Tumour usually involves the right heart chambers and pericardium. With advances in imaging, early diagnosis is possible and treatment including chemotherapy and surgery affords good prognosis.

Case Presentation: We present a 50-year-old woman with abdominal pain and fevers for 5 days. Computed tomography of the abdomen showed splenic and renal infarcts but no mass or vegetation was noted on echocardiography. Thoracic computed tomography divulged a large left ventricular filling defect. Cardiac magnetic resonance imaging delineated a 3.5 × 4.5 cm anterobasal mass with frond-like projections and endocardial invasion without extracardiac involvement suggestive of a low-vascularity tumour. Echo-guided endomyocardial biopsy and minithoracotomy with needle biopsy were inconclusive. A sarcoid-protocol cardiac positron emission tomography-fluorodeoxyglucose scan showed focally elevated uptake in the basal anteroseptum without extracardiac uptake, supporting a malignant entity. This prompted open heart mass resection. Pathology revealed diffuse large B-cell lymphoma.

Discussion: Our case is a unique report of cardiac lymphoma isolated to the left ventricle. Location of the tumour and lack of specific imaging characteristics made it a diagnostic challenge. It underscores the importance of including lymphoma in the differential for intracardiac masses as it is responsive to chemotherapy. Additionally, it emphasizes the complementary role of imaging modalities and multidisciplinary team approach in diagnosis. Early diagnosis and therapy is the key to establishing successful outcomes.