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CT AND MRI FINDINGS OF RIGHT CARDIAC TUMOR REVEALING A DISSEMINATED LYMPHOMA: A CASE REPORT

H RIAHI, Y AROUS, M LANDOLSI, S KOUKI, H BOUJEMAA, N BEN ABDALLAH Radiology Department, Military Hospital of Tunis, Montfleury, Tunis, Tunisia

E mail: younesmutu@yahoo.frCR11INTRODUCTION Metastases to the heart and pericardium are much more common than primary cardiac tumors and are generally associated with a poor prognosis.

In autopsies at which a malignant neoplasm was diagnosed, cardiac metastases were found in 9.7% 10.7% of case.

Tumors that are most likely to involve the heart and pericardium include cancers of the lung and breast, melanoma, and lymphoma2HISTORYA 30 year old woman presented with acute dyspnea and palpitations.

A transthoracic echocardiography was performed and showed a mobile echogenic mass.

Whole body CT and cardiac MRI were performed.

3 IMAGING FINDINGSHole body CT (64-section, General Electric)

Cardiac MR (Siemens Verio 3 Tesla): Turbo spin-echo T1-weighted before and after contrast administration imagesT2- weighted images (HASTE)Steady state free precession imagesDelayed enhancement images

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Contrast enhanced CT scan: low attenuation mass of the right atrium and ventricle () and a pericardial effusion5

Contrast enhanced CT scan: left retroperitoneal mass ()6

Contrast enhanced CT scan: bilateral ovarian masses7

Axial T1-weighted image before administration of gadolinium: isointense mass of the right cavities ()and a thickening of the interatrial septum()Axial T2-weighted image (HASTE): slightly hyperintense mass of the right cavities8

Two-chamber and short-axis steady-state free precession images: mobile massoccupying almost the entire right cavity and a thickening of the right ventricular wall()and and the inferior wall of the left ventricle( )9

Axial, two chambers and short axis T1-weighted images after administration of gadolinium show heterogeneous enhancement of the right mass and the thickening of the interatrial septum and the inferior wall of the left ventricle.10

Short-axis and two chambers delayed enhanced sequences: heterogeneous enhancement 11A life-saving emergency operation was carried. The pathology report with immunostaining confirmed a diagnosis of B cell lymphoma.

A CT control showed a significant response to chemotherapy estimated to 80 %

12DISCUSSION EPIDEMIOLOGIC FEATURES

Cardiac metastases are far more common than primary involvement, with an estimated ratio of 30:1.

In the presence of a malignant tumor, cardiac metastases are found in 9.7%10.7% of cases.

The tumors that most frequently metastasize to the heart and pericardium are lung and breast cancers, melanomas, and lymphomas.13Involvement of the heart and pericardium is usually a late manifestation of lymphoma; the median time of onset is 20 months after initial diagnosis.

The tumors usually arise from the right side of the heart, often the right atrium, with frequent involvement of more than one chamber and are accompanied by a large pericardial effusion.

In approximately one third of patients with cardiac involvement, death will be directly attributable to the metastases as a result of pericardial tamponade, congestive cardiac failure, or coronary artery invasion

14CLINICAL FEATURES

Although cardiac metastases from lymphoma are frequently found at autopsy, they are rarely diagnosed because most patients (90%) are asymptomatic

When present, the clinical signs and symptoms of cardiac metastases are nonspecific and include: Fatigue, Superior vena cava syndrome, Congestive heart failure, Cardiac arrhythmia, Pericardial effusion, Obstructed right ventricular inflow or outflow, Transient ischemic attack15Arrhythmia remains the most common clinical sign of cardiac metastases, and its sudden appearance raises the possibility of cardiac metastatic involvement.

Tumor involvement and its consequences (cardiac tamponade, congestive heart failure, coronary artery invasion, sinoatrial node invasion) are the cause of death in one-third of patients with cardiac metastases.

16IMAGING FEATURES

1. CHEST RADIOGRAPHY:

cardiomegalypericardial effusionsigns of heart failure

2. ECHOCARDIOGRAPHY:

Cardiac mass in the right atrium or ventricle pericardial effusion173. CT:

lymphomas are hypoattenuating or isoattenuating relative to the myocardium

heterogeneous enhancement after intravenous administration of contrast material184. MR IMAGING:

poorly marginated and heterogeneous lesions

lobulated

isointense to slightly hypointense relative to cardiac muscle on T1-weighted MR images

isointense to slightly hyperintense on T2-weighted images.

Gadolinium administration produces a heterogeneous pattern of enhancement.

19CONCLUSIONMetastases to the heart occur late in the course of malignant disease. The patient typically has metastatic disease at other sites (usually pulmonary metastases are present).

Cardiac or pericardial locations are rarely the first sites of malignant disease.

Neoplasms with the highest frequency of cardiac and pericardial metastases include melanoma, leukemia, and lymphoma.

20Involvement of the heart and pericardium is usually a late manifestation of lymphoma.

Our knowledge, it is the first case where a cardiac mass reveal a disseminated lymphoma.

The tumor usually arise from the right side of the heart, often the right atrium, and are accompanied by a large pericardial effusion.

21MRI is presently the modality of choice to evaluate cardiac tumors.

High contrast resolution and multiplanar capability allow a specific diagnosis and optimal evaluation of myocardial infiltration, pericardial involvement and extracardiac extension.

Acquisition of postcontrast sequences enables better depiction of tumor vascularity and can be used to define tumor borders.

MRI has an important role in differentiating thrombi from cardiac tumors

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