Diffuse myocardial infiltration in secondary cardiac lymphoma: A case report

Abstract

Cardiac lymphomas are rare, with a high proportion developing as secondary lymphomas. The symptoms of secondary heart lymphoma are often nonspecific and may not be detected promptly, leading to a poor prognosis. This case report describes the case of a 53-year-old male patient diagnosed with diffuse large B-cell lymphoma originating in the thymus. Prior to treatment, ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) confirmed the diagnosis of diffuse lymphoma invasion in the heart. After chemotherapy, the cardiac lesions largely regressed. Cardiac magnetic resonance imaging, echocardiography and PET/CT revealed post-chemotherapy tumor necrosis and fibrosis in the myocardium, resulting in the formation of a left ventricular aneurysm. This case report discusses the diagnosis and treatment of secondary cardiac lymphoma, focusing on diffuse myocardial infiltration as the primary manifestation.

Keywords: cardiac lymphoma; case report; diffuse myocardial infiltration; secondary heart lymphoma.

Figure 1.

Chest enhanced CT and pathological images before treatment. (A) Masses in superior mediastinum (red arrow). (B) Enlargement of the heart with a predominant enlargement of the left ventricle, thickening of the pericardial wall and a small amount of fluid accumulation in the pericardial cavity. (C) Hematoxylin and eosin staining image shows proliferative lesions in lymphoid tissue, disappearance of follicular structures and significant cellular pleomorphism. (D and E) Immunohistochemical staining images positive for (D) CD20 and (E) paired box gene-5 (magnification, ×200; scale bars, 100 µm).

Figure 2.

PET/CT imaging prior to treatment. (A) PET maximum intensity projection: Multiple high-glucose metabolism lymph nodes above and below the diaphragm (black arrows; SUVmax: 13.5) and multiple high-glucose metabolic lesions in the pancreas (red arrows; SUVmax: 15.5). (B) PET/CT fusion axial images of the mediastinum: Global and diffused accumulation of high-glucose metabolic lesions in the mediastinum and heart (SUVmax: 14.9), with the involvement of both ventricles, interventricular septum and atria. (C and D) PET/CT fusion axial images: Localized increased glucose metabolism in (C) the right third rib axilla and (D) 10th thoracic vertebrae (white arrows; SUVmax: 9.3). PET/CT, positron emission tomography/computed tomography; SUVmax, maximum standardized uptake value.

Figure 3.

Imaging examination before treatment. (A) MRI T2-weighted imaging axial image: Significant thickening of the left ventricular wall and increased T2 signal (red arrow). (B) MRI DWI axial image: Increased DWI signal in the left ventricular wall, indicating diffusion limitation (red arrow). (C) Short axis echocardiography: Widespread thickening of the heart wall. MRI, magnetic resonance imaging; DWI, diffusion-weighted imaging.

Figure 4.

Imaging examination after treatment. (A) PET maximum intensity projection: A reduction in heart volume, elevated glucose metabolism in the left ventricular wall (black arrow), along with complete remission of the remaining lymphoma lesions. (B) PET/computed tomography fusion axial images of the mediastinum: Increased glucose metabolism in certain areas of the left ventricular wall (maximum standardized uptake value: 12.4). (C) Left ventricular long axis echocardiography: An aneurysm (red arrow; length, ~49.7 mm; width, ~23.8 mm) of the left ventricular apex with associated wall thrombus formation. (D) Cardiac magnetic resonance imaging delay enhancement image: Extensive enhancement of the ventricular wall (red arrow), indicating possible residual myocardial fibrosis or lymphoma. PET, positron emission tomography.