CASE 13950 Published on 21.08.2016

Pericardial sarcomatoid mesothelioma with right atrial involvement: Cardiac MRI findings



Case Type

Clinical Cases


Noura Abdelmonem Nooman, Mohamed A. Eltomey

Diagnostic Radiology and Medical Imaging department,
Faculty of Medicine,
Tanta University,

30 years, female

Area of Interest Cardiac ; Imaging Technique MR
Clinical History
The patient presented with attacks of syncope, elevated liver enzymes & generalized oedema associated with recurrent haemorrhagic pericardial effusion after drainage for 3 times. History of preeclampsia 4 months ago was given as well. On physical examination, the patient appeared pale.
Imaging Findings
Echocardiographic-Doppler study: showed massive amount of pericardial effusion, decreased right ventricular function and a right atrial intraluminal echogenic mass.

CMRI study showed:
*A well-defined mass with lobulated margin measuring 6 x 7 x 6.5 cm, inseparable from the roof, inferior & lateral walls of the right atrium displaying low signal intensity with high signal areas in T1WI & high signal intensity in T2WI. It showed heterogeneous enhancement after contrast injection. The mass is attached to the overlying pericardium with infiltration of the infero-lateral wall of right atrium. It reached the right atrio-ventricular junction and minimally bulged into the IVC ostium. No extension into the right ventricle, SVC or IVC lumen was seen.
*A large amount of mixed signal pericardial fluid.
*Normal right & left ventricular functions.

Chest CT study: confirmed the presence of the right atrial intraluminal mass with bilateral pleural effusion& few enlarged mediastinal lymph nodes.

Abdominopelvic CT: showed a right hepatic lobe haemangioma.
Mesothelioma is a malignancy of the serous epithelial cells of the pleura, peritoneum, pericardium and the testicular vaginal epithelium. Malignant pericardial mesothelioma is very rare and highly lethal [1]. Primary cardiac tumours are very rare; metastases to the heart are more common. Most of primary heart tumours are benign. Cardiac sarcomas include angiosarcomas, rhabdomyosarcomas, malignant mesotheliomas and fibrosarcomas. Angiosarcoma is the most common type affecting adults [2].

Patients usually present clinically with shortness of breath due to pericardial effusion or heart failure [3]. Cardiac tamponade is a frequent symptom. Imaging is needed to determine the tumour location and tumour resectability [2]. Differentiation between malignancy and reactive hyperplasia is important. Deep tissues infiltration indicate a malignancy. Metastases occur to the regional lymph nodes, lungs and kidneys [1].

Diagnostic procedures include plain chest X-ray, Echocardiography, Computed Tomography (CT) and Cardiac Magnetic Resonance Imaging (CMRI). The plain chest X-ray may show a mass lesion in the form of cardiac shadow enlargement [2].

Echocardiography is usually the initial imaging procedure as it can assess the valves, function of the ventricles and intracardiac masses but it is operator-dependent with a restricted field of view. Differentiation between thrombi, benign and malignant tumours is often difficult [2, 4].

CT can assess tumour site, extent and presence of calcification. Detection of enhanced soft tissue pericardial nodules is helpful for the diagnosis. It is an alternative procedure when CMRI cannot be performed. CT uses ionizing radiation and has inferior soft-tissue resolution compared to CMRI [3, 4].

CMRI is essential for the assessment of cardiac tumours due to its ability to characterize tissues and to view the heart and surrounding structures. It can confirm the tumour site and differentiate between the benign & malignant lesion. The CMRI features suggesting malignancy are: invasion of surrounding structures, right-sided heart lesions, heterogeneity, ill-defined borders, >5 cm diameter, and presence of pericardial or pleural effusion [5]. Pericardial mesothelioma may present as a multinodular heterogeneous mass within the pericardial space [6].

The prognosis is poor even with adjuvant chemo-radiotherapy and it is difficult to perform complete surgical resection [4]. Death occurs on average in less than 6 months [6].

CMRI is the reference technique for evaluation of tumour extent and nature. The standard CMRI protocol is usually sufficient with postcontrast and cine sequences being vital in the assessment of the vascularity, mobility and attachment of these masses. Familiarity with the characteristic radiologic features of benign and malignant lesions will influence diagnosis and treatment plan [4].
Differential Diagnosis List
Pericardial sarcomatoid mesothelioma infiltrating the right atrium
Metastasis to the pericardium either from distant malignancy or from the surrounding structures
Cardiac angiosarcoma
Pericardial fibrosarcoma
Final Diagnosis
Pericardial sarcomatoid mesothelioma infiltrating the right atrium
Case information
DOI: 10.1594/EURORAD/CASE.13950
ISSN: 1563-4086