1. 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
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2. INTRODUCTION
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 lymphoma

3. HISTORY
A 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.

4. IMAGING FINDINGS Hole body CT (64-section, General Electric)
Cardiac MR (Siemens Verio 3 Tesla):
Turbo spin-echo T1-weighted before and after contrast administration images
T2- weighted images (HASTE)
Steady state free precession images
Delayed enhancement images

5. ★
Contrast enhanced CT scan: low attenuation mass of the right atrium and ventricle (★) and a pericardial effusion

6. Contrast enhanced CT scan: left retroperitoneal mass ()

7. Contrast enhanced CT scan: bilateral ovarian masses

8.  ★
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 cavities

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

10. 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.

11. Short-axis and two chambers delayed enhanced sequences: heterogeneous enhancement

12. A life-saving emergency operation was carried
A 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 %

13. DISCUSSION
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.

14. Involvement 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

15. CLINICAL 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 attack

16. Arrhythmia 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.

17. IMAGING FEATURES
1. CHEST RADIOGRAPHY:
cardiomegaly
pericardial effusion
signs of heart failure
2. ECHOCARDIOGRAPHY:
Cardiac mass in the right atrium or ventricle

18. 3. CT:
lymphomas are hypoattenuating or isoattenuating relative to the myocardium
heterogeneous enhancement after intravenous administration of contrast material

19. 4. 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.

20. CONCLUSION
Metastases 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.

21. Involvement 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.

22. MRI 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