Diffuse large B-cell lymphoma of non-germinal center B-cell type of the heart in an immunocompetent woman: an autopsy case.

Primary lymphoma of the heart is extremely rare and almost always occurs in immunodeficient persons. The author reports a very rare autopsy case of primary diffuse large B-cell lymphoma in an immunocompetent woman. A 55-year-old woman presented with chest pain and arrhythmia. Various imaging modalities including US, CT, MRI, and gallium-scintigraphy revealed a mass in the right atrium and pericardial effusion. No tumor formations were recognized in other organs. Pericardial effusion cytology revealed malignant large lymphoid cells of B-cell type positive for CD20. Laboratory data did not reveal immunosuppression, and human immunodeficiency virus was negative. Therefore, a clinical diagnosis of primary heart lymphoma was made. The patient was treated with chemo-radiation, but died of heart failure 4 years after the first presentation. An autopsy revealed a tumor formation (4 × 5 × 6 cm) in the right atrium and ventricle of the heart. No tumor formation was recognized in other organs. Histological and immunohistochemical studies showed that the cardiac tumor was diffuse large B-cell lymphoma of non-germinal center B-cell type; tumor cells were positive for CD45, CD20, CD79α, bcl-2, and λ-chain, but negative for EBV latent membrane antigen 1, CD10, bcl-6 and MUM1. Epstein-Barr virus protein and DNA were negative by immunohistochemistry and in situ hybridization. It was suggested that primary lymphoma of the heart may occur in immunocompetent persons. This is the first report of diffuse large B-cell lymphoma of the heart with a classification of non- or germinal center B-cell type.