Primary Cardiac Angiosarcoma with Pericardial Metastasis

A Rare Case Report

Abstract

Primary cardiac angiosarcoma is a rare and aggressive malignant mesenchymal neoplasm. They show endothelial differentiation in morphology and immunohistochemistry. There is a male predominance, common in the western world, and the age of presentation being fourth to sixth decades. The prognosis is worse as compared to other sarcomas due to the high chance of developing cardiac tamponade. We report the case of a 30-year-old male who presented with chest pain and shortness of breath. The patient complained of pain due to recurrent pericardial effusion which was drained and sent for cytological examination. The fluid was negative for any malignancy and inflammatory pathology. However, his symptoms worsened and a cardiac magnetic resonance imaging was suggestive of a right atrial tear and pseudoaneurysm suspected iatrogenic injury from the previous pericardiocentesis at another hospital before admission. The patient underwent emergency sternotomy for cardiac tamponade with right atrial repair and the removed clot and pericardium were sent for histopathology. Histopathology and immunohistochemistry surprisingly revealed angiosarcoma in the pericardial patch tissue. Unfortunately, the patient died postoperatively. Angiosarcomas are the most common cardiac malignant tumors. It has an aggressive course with poor prognosis and variable clinical presentation. Histopathology with immunohistochemistry plays a definite role in diagnosing these tumors. Hence, its awareness is a must among clinicians and pathologists.

INTRODUCTION

Primary cardiac tumors are sporadic, with an estimated prevalence of 0.001%–0.03% at autopsy. Most of the primary cardiac tumors are benign. Sarcomas are the most common primary malignant tumor, with angiosarcomas being the most common, and account for 50%–75% of cases.[¹] Treatment of angiosarcomas remains controversial due to its rarity and late presentation. Surgery is the first line of treatment but alone is not adequate. The effectiveness of adjuvant chemotherapy, radiotherapy, and surgery is not yet established.[²³] More cases need to be reported to understand the nature and treatment of this tumor.

CASE REPORT

A 30-year-old male patient presented to the emergency department with complaints of fatigue, chest pain, and shortness of breath. He had a history of admission to another hospital with recurrent pericardial effusion. The patient underwent pericardiocentesis, which yielded blood-mixed fluid and no tumor cells on cytology. The patient had temporary relief of symptoms after the procedure, but gradually symptoms worsened over 2 weeks, and the patient presented to our institute with shortness of breath and chest pain. Routine laboratory examination revealed low hemoglobin and other parameters were within normal limits. His vitals were stable. A chest radiograph was done, which suggested pericardial effusion. Cardiac magnetic resonance (MR) findings revealed a right atrial tear, hemopericardium, and multiple hypoenhancing foci within the corresponding pericardial space, suggestive of a clot. The patient underwent emergency surgery through a midline sternotomy with relief of cardiac tamponade and repair of a right atrial tear. Unfortunately, the patient died postoperatively. The clots and soft tissue removed were sent to the histopathology department. A gross examination of the specimen revealed multiple deep brown-to-black tissue pieces [Figure 1]. Microscopic study of both clot and pericardial patch revealed similar findings and showed atypical pleomorphic spindle cells arranged in fascicles and solid lobules around blood vessels [Figures 2 and 3]. Brisk mitosis and broad areas of hemorrhage were present. Tumor cells were immunoreactive for CD31, CD34, and vimentin. Ki-67 labeling index was 40% [Figure 4a-c]. The tumor cells were negative for cytokeratin, MDM-2, smooth muscle antigen [Figure 4d], desmin, Myo-D, myogenin, and S-100. The features were of poorly differentiated angiosarcoma.

Figure 1: Gross specimen shows multiple irregulars and globular gray, white-to-dark brown to black tissue pieces.

Figure 2: Low-power microscopic photograph shows areas of hemorrhage with tumor cells (H and E, ×4).

Figure 3: Hematoxylin and eosin-stained sections show atypical, spindled cells showing moderate pleomorphism and lining vascular channels (H and E, ×40).

Figure 4: (a-d) Tumor cells are immunoreactive to CD34, CD31, Ki67 – 70%, and SMA is negative (×20). SMA: Smooth muscle antigen.

DISCUSSION

Angiosarcoma is the most common primary malignant tumor of the heart, accounting for 31% of all malignant tumors. It usually affects people from 30 to 50 years of age. Owing to their varied clinical presentation, they pose a significant diagnostic challenge to clinicians, leading to delays in their diagnosis. However, the common presenting symptoms are chest discomfort, dyspnea, palpitations, generalized weakness, and symptoms associated with heart failure. They arise in the right atrium, followed by other heart chambers.[⁴] The etiology is generally unknown. However, they may occur secondary to chest radiation cases in Li-Fraumeni-like families that have been reported.

They are usually diagnosed at a late stage, and most of them have metastasis at the time of diagnosis.[⁵] The common sites of metastasis are the lung and pericardium.[⁶]

Imaging is critical for better delineation of these tumors. The initial diagnostic modality remains transthoracic echocardiography with a sensitivity of 93%. Computed tomography (CT) and MR imaging function as an additional valuable tool for identifying tumor infiltration and characterization. 18F-fluorodeoxyglucose positron emission tomography-CT is a noninvasive technique that can identify these tumors with a sensitivity of 100%. Pericardial fluid aspiration usually yields hemorrhagic fluid with negative cytology. The patient also presented with recurrent pericardial effusion, and on pericardiocentesis yielded a hemorrhagic fluid without any tumor cells.[⁷]

However, histopathology remains the mainstay of diagnosis despite the availability of many imaging modalities. On gross examination, angiosarcomas are deep brown to black, ranging from 2 to 10 cm in size. They usually occupy the atrial cavity and infiltrate the myocardium and pericardium. The microscopic picture of these tumors varies depending on the degree of differentiation. Well-differentiated tumors usually show pleomorphism in vascular spaces or papillary structures lined by atypical endothelial cells. Whereas poorly differentiated tumors usually show anaplastic spindled cells arranged in solid nests and lobules. On immunohistochemistry, they show positivity for CD31 (90%), CD34 (50%–74%), and Friend leukemia integration 1 (FLI-1) (100%). Ki-67 labeling index with a value of >10% is associated with a bad prognosis.[⁸⁹] Our case was consistent with poorly differentiated angiosarcoma with atypical, spindled cells arranged in fascicles and solid lobules around vessels and showed positivity for CD31 and CD34 with a high Ki-67 of 40%.

Owing to these neoplasms' rare and aggressive nature, the treatment protocol is not yet standardized. Total surgical resection remains the treatment of choice. However, recurrence is common. The effectiveness of adjuvant therapy, chemotherapy, or radiotherapy is debatable due to its rarity and lack of data from extensive studies. They are very aggressive tumors with a dismal prognosis and overall survival remains between 6 and 12 months. The role of different chemotherapeutic regimens remains unclear due to the rarity of these tumors. The most used regimens by oncologists are adriamycin based. However, other frequently used drugs include ifosfamide, vincristine, cyclophosphamide, and dacarbazine.[²³] Cardiac transplantation is an alternative treatment option, but there is no unmistakable evidence of survival benefits in patients undergoing transplantation than those in whom it is not conducted.[¹⁰]

CONCLUSIONS

Primary cardiac tumors are rare, with angiosarcomas being the most common malignant tumor. Cardiac angiosarcomas are aggressive tumors with poor prognoses. Due to their varied clinical presentation and aggressive nature, it is difficult to diagnose them logically. Therefore, histopathology with immunohistochemistry plays a pivotal role in diagnosing these tumors.

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The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

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Conflicts of interest

There are no conflicts of interest.