Episode Schematics & Teaching

Pearls – primary cardiac angiosarcoma

1. The pericardium is composed of an outer fibrous sac, and an inner serous sac with visceral and parietal layers.  

2. Pericardial masses can be primary (benign or malignant) or metastatic. There are other miscellaneous pericardial masses. 

3. Imaging modalities for the pericardium include echocardiography, cardiac CT and cardiac MRI. There is also role for PET-CT in pericardial imaging for further characterization of pericardial masses.  

4. Cardiac angiosarcomas are extremely rare but are the most common cardiac primary malignant tumors. 

5. Evidence-based management if lacking because of paucity of clinical data given the rarity of cardiac angiosarcomas. Surgery is the mainstay of therapy. Radiotherapy and chemotherapy are often used as well. 

Notes – primary cardiac angiosarcoma

Pericardial Anatomy 

The pericardium is a fibroelastic sac composed of two layers.  

1. Outer layer: fibrous pericardium (<2 mm thick) 

2. Inner layer: serous pericardium, two-layered sac. 

• Visceral pericardium: adherent to underlying myocardium 
• Parietal pericardium: lines fibrous sac. 

• Between the serous layers, there is the pericardial cavity which normally contains up to 50 cc pericardial fluid. 

Pericardial Masses 

Benign 

• Lipoma: slow-growing, collection of adipose cells, thought to arise in AV groove 
• Teratoma: benign germ cell tumors, often right sided. Can cause compressive symptoms of RA, SVC, PA, aortic root.  
• Fibroma: solid mass of connective tissue 
• Hemangioma: vascular mass, often arising from visceral pericardium 

Malignant 

• Sarcoma: various types including angiosarcoma and liposarcoma.  
• Lymphoma: usually non-Hodgkin B-cell lymphoma, often in immunocompromised patients 
• Mesothelioma: no apparent association with asbestos. Pericardial effusions with nodules/plaques are seen. 

Metastatic 

• Often associated with hemorrhagic pericardial effusions 
• Breast cancer, lung cancer, melanoma and renal cell carcinoma are most common 

Pericardial Imaging 

Echocardiography 

Advantages:  

• widely available 
• low cost  
• safe 
• can be performed in multiple settings (e.g., HD unstable) 

Disadvantages:  

• limited view/windows 
• operator dependent 
• technical difficulties (lung disease, obesity, surgical bandages) 

• limited tissue characterization 

Cardiac Computed Tomography 

Advantages: 

• Superior tissue characterization compared to echocardiography 

• Can identify extra-cardiac disease 
• Identification of calcification 
• Pre-operative planning 
• High spatial resolution  

Disadvantages:  

• Use of ionizing radiation and iodinated contrast 
• Difficult gating in patients with tachycardia/arrhythmias; use of breath hold 
• HD stable patients only 

Cardiac Magnetic Resonance Imaging 

Advantages: 

• Superior tissue characterization compared to echocardiography/computed tomography 

Disadvantages: 

• Time consuming, expensive 
• Difficulty gating in patients with tachycardia/arrhythmias; use of breath holds for some sequences 
• Challenges in patients with electronic implants 
• Use of gadolinium contrast 
• Extra-cardiac structures not well visualized; calcifications less well-visualized 

Positron Emission Tomography/Computed Tomography (PET/CT) 

Has been shown to be an effective additional imaging modality in patients in whom cardiac mass is suspected to be malignant, and helps provide further confirmation and screening for metastatic disease.  

Angiosarcoma of the Pericardium 

• Very rare, but most common cardiac primary malignant tumor. 
• Typically right-sided and secondarily involves the pericardium. 
• Primary pericardial angiosarcoma usually occurs in middle-aged, more frequently in males. 
• Often metastatic at time of diagnosis.  
• Clinical presentation 
• Variety of symptoms, and often undetected early on. 
• Symptoms include dyspnea, chest pain, cough, fatigue/malaise, and signs of caval obstruction.  
• Clinical picture rapidly deteriorates as it can eventually result in intractable heart failure and death due to multi-organ failure.  

Lab/Imaging Tests 

• Tumor marker CA125 elevated. 
• Pericardiocentesis usually reveals bloody fluid (containing RBCs, WBCs). Cytology often misses malignant cells.  
• EKG can show non-specific ST-T wave abnormalities and low QRS voltage. 
• CXR may show an enlarged cardiac silhouette.  
• Transthoracic echocardiography can show pericardial effusion but may fail to show echogenic mass if no good acoustic windows. Large masses in the pericardium may be seen in some patients.  
• CT can show location, size, and extent of mass. 
• CMR can further show tumor necrosis or hemorrhage. Can help characterize and stage tumors. 
• PET/CT can help detect metastasis from pericardial tumors.  
• Definitive diagnosis = biopsy (mediastinoscopy, exploratory pericardiotomy or thoracotomy). Extensive excision is usually recommended. Angiosarcomas histologically are characterized by presence of anastomosing vascular channels that are lined by atypical/malignant endothelial cells showing frequent mitoses.  
• Immunohistochemical staining: endothelial markers (CD31, CD34, vimentin, factor VII). 

Management 

• Because of rarity there is little clinical evidence-based data for management. 
• Usually responds poorly to chemotherapy and radiation. 
• Surgery is challenging because these tumors are diagnosed late and there is already metastatic disease. 
• Orthotopic cardiac transplantation is sometimes done and has prolonged life, though incidence of metastatic disease limits utility. Could be helpful in patients who have unresectable but locally aggressive tumors without metastasis. 
• Palliative treatment options are usually resorted to because the disease often presents so late. Length of survival after diagnosis ranges between 6-11 months.  
• Ultimately, surgical resection with negative margins is associated with best outcome; there is some benefit to then adding chemotherapy and radiotherapy.