A Patient Presenting with Cardiac Tamponade and the Challenges of Finding Its Cause: A Cardiac Angiosarcoma

Primary malignancies of the heart are so rare that most of the available data come from case reports or large single-center-based studies, with the overall incidence of 0.02% in the United States. Diagnosis in case of an isolated pericardial effusion as presentation is challenging, and determining that an angiosarcoma is even more challenging. Here, we presented a rare case of pericardial angiosarcoma which presented to us with tamponade. The patient eventually was diagnosed through pericardiectomy. A multimodality approach was attempted to treat the cancer. The clinical details of such a unique disease entity inspired us to present it as a case report.


Introduction
Pericardial angiosarcoma is a rare form of primary malignancy of the heart. Due to its insidious nature, most cases present with advanced disease with poor outcome. Diagnosis is challenging, demanding a panel of experts. ere is no guideline for treatment. Hereby, we present a unique case of tamponade caused by primary angiosarcoma.

Case Description
On May 2016, a 59-year-old Bulgarian male referred from the o ce of cardiologist to our hospital complaining of worsening shortness of breath, weight gain of 6 pounds, leg swelling, and low blood pressures (BP) down to 80/60 mmHg for a few weeks. Medical history was signi cant for hypertension, coronary artery disease, diabetes, atrial brillation, polycystic kidney disease, and a recent tamponade diagnosed 4 months prior to this hospitalization. Dizziness was his initial complaint in March. A large serosanguinous pericardial effusion was drained at that time with inconclusive uid analysis including a negative culture and cytology. His medications included amlodipine, lisinopril, and atorvastatin. He used to work as a truck driver. After 45 packs per year smoking history, he quit in 2015. Positive ndings on exam were a BP of 85/60 mmHg, mild respiratory distress on room air, increased jugular vein pressure, mu ed irregular heart sounds, and pitting edema of the shins. Echocardiography showed normal left ventricular ejection fraction of 59% and a moderate sized posterior pericardial e usion with borderline signs of tamponade.
e echo also revealed a brinous material and stranding suggestive of adhesions in the collection (Figure 1). Attempt to drain the pericardial e usion with subxiphoid pericardial window was terminated due to fusion of pericardium to the anterior surface of right ventricle. Partial pericardiectomy was then attempted through median sternotomy with frozen section, which revealed a neoplastic process. Hence, a subtotal pericardiectomy was performed.
ese ndings led to the diagnosis of epithelioid angiosarcoma of the pericardium. Chest computed tomography scan showed nodular opaci cations within both lungs with concern for metastasis. His condition stabilized with Lasix and oxygen. He was then referred to the university hospital for a second opinion regarding his management. Cardiac MRI showed extensive vascular malignant mass in the pericardium encircling and in ltrating the right heart chambers. He received paclitaxel weekly for 6 doses with palliative intents. Later he developed malignant pleural e usions and intracranial metastatic lesions. He was admitted again in our hospital for weakness and encephalopathy. Patient preferred comfort care. Hence, he passed away 9 months after his initial presentation.

Conclusion
Primary pericardial neoplasms are rare entities with estimated prevalence of 0.001 to 0.007% based on mostly case series studies [1,2]. Mesothelioma is the most common malignancy followed by di erent subtypes of sarcomas and lymphoma [1]. Angiosarcomas account for a third of sarcomas of the heart, and the majority arise in the right atrium.

Case Reports in Cardiology
It can be seen at almost any age with peak incidence in middle-aged men. e majority are asymptomatic until they become large enough to cause symptoms. Presentation depends on area of involvement, such as emboli or obstruction in case of intracardiac lesion, arrhythmia with myocardial involvement, and pericardial e usion from pericardial raised tumor. Pericardial angiosarcoma may arise from the epicardial surface of the heart and penetrate the pericardial space. Signs of right-sided heart failure and pericardial e usion are common, which can lead to tamponade. In one study, pericardial e usion was common, but pericardial uid cytology was negative in all patients who underwent pericardiocentesis [3]. By the time of diagnosis, most patients have metastases, most commonly to the lung [4].
Histologically, angiosarcomas consist of endothelial cells, spindle cells lining, and not well-de ned anastomotic vascular spaces, causing sheet-like pericardial thickening. Malignant cells are positive for CD31, CD34, and factor VIII and form vascular channels con rming endothelial di erentiation [5]. About 90% of patients die within the rst year of diagnosis without resection [6]. Patients who receive multimodality treatment options (combination of surgery, radiation therapy, and chemotherapy) have improved survival compared to patients treated with only one modality. Even with all these strategies, longest survival remained less than 3 years [7]. Cardiac transplantation is not currently recommended due to poor survival bene t in few studies [8], except for very selected group of patients with subsequent immunotherapy [9]. Genome sequencing of the tumor in attempt to target gene therapy against vascular-speci c receptor tyrosine kinases is currently being studied [2]. e optimal treatment strategy remains to be discovered. e diagnosis of heart angiosarcoma in our patient was challenging due to absence of a mass in di erent imaging of the heart, resulting in diagnostic pericardiectomy as only de nite modality. Still, possibility of malignant tumor should be always considered in cases of recurrent serosanguinous pericardial e usions specially with a negative uid cytology.

Summary
Primary malignancies of the heart are so rare that most of the available data come from case reports or large single-centerbased studies, with the overall incidence of 0.02% in the United States. Diagnosis in case of an isolated pericardial e usion as presentation is challenging. Unique pathologic features include endothelial cells, spindle cells lining, and vascular spaces. Despite surgical approaches and di erent chemotherapeutic regimens, prognosis is poor with mean survival of up to 3 years. Di erent modalities such as heart transplantation, immunotherapy, and targeted gene therapy are recently being studied.

Disclosure
is case has been presented as an abstract at the Society of General Internal Medicine Annual Meeting in 2017.