Brugada phenocopy with altered ST-segment elevation in pericardial diffuse large B-cell lymphoma and effusive-constrictive pericarditis: a case report.

Background: Cardiac lymphoma is a rare disease. Effusive-constrictive pericarditis can be a characteristic of pericardial involvement in patients with this disease. Conversely, a phenotype with electrocardiogram changes similar to those of Brugada syndrome is called Brugada phenocopy, and these changes improve after treatment. Case summary: A 71-year-old man was transported to our hospital with chest pain, hypotension, and ST-segment elevation in V1 and V2 leads during maintenance dialysis for renal failure. After arrival at the hospital, his ST-segment elevation disappeared, and emergency coronary angiography scan revealed no significant coronary artery stenoses or obstructions. His computed tomography and echocardiography scans revealed pericardial effusion and an intrapericardial mass. Further, his blood pressure dropped and ST-segment elevation recurred during dialysis after 7 days. Thus, pericardiocentesis was performed, but haemodynamic improvement was insufficient, and right catheterization findings suggested effusive-constrictive pericarditis. Meanwhile, flow cytometry of the pericardial fluid suggested the diagnosis of B-cell lymphoma; however, radical chemoradiotherapy was impossible because of cardiogenic shock. The patient died on Day 17. Further, autopsy revealed diffuse large B-cell lymphoma with pericardial and myocardial infiltration. Discussion: Cardiac lymphoma is rare but can be associated with effusive-constrictive pericarditis, which may be difficult to manage even with pericardial drainage. In such cases, radical treatment, including chemotherapy, should be promptly considered, if possible. Our patient presented with Brugada-type electrocardiogram but no syncope or family history, suggesting Brugada phenocopy and not true Brugada syndrome due to cardiac lymphoma. Notably, temporary improvement in ST-segment elevation was observed despite the absence of treatment.