Pericardial Synovial Sarcoma (PSS) is a rare malignant soft-tissue tumor. Early diagnosis and multimodal management could be improving patient outcome. PSS diagnose is difficult due to localization but an aggressive disease. Using all the available medical methods is important to avoid progression and recurrence of this kind of tumors. Multidisciplinary treatment is necessary, and radiotherapy is a good and safe option. We present our experience of a forty-year-old man with this tumor.
Pericardial synovial sarcoma is a type of sarcoma uncommon . It is usually diagnosed in young adults. Patient’s present unspecific symptoms, like fever, cough, pain chest and fatigue. In other cases, patients present pericardial effusion and cardiac tamponade. Only 30 cases of synovial sarcoma of the pericardium have been reported in the English language literature, 20 included follow-ups [2,3].
The purpose of this report is to describe the case of a patient with pericardial synovial sarcoma whose initial presentation was severe pericardial effusion. Despite treatment, the patient died in one year. Then, we reviewed the medical literature for the epidemiology, clinical picture, and relevance of complementary imaging tests, therapeutic conduct and prognosis of this neoplasm.
40-year-old man visited our Hospital in June 2014 due to chest pain. The physical examination had no abnormal findings. After admission, the chest X-ray indicated cardiomegaly and echocardiography showed dates of pericardial effusion. The patient received treatment and was discharged from hospital after one week with pericarditis diagnosis. Four months later, he started with similar symptoms and echocardiography showed massive pericardial effusion with a tumorous region in the pericardial space. Echocardiography showed a big mass with compression of right cavities without stenosis, gradient valve
tricuspid of 3,7mmHg. The chest CT, as well as confirming the effusion, revealed a pericardial cystic mass with pericardial thickening (Figure 1). Is suggested of neoplasm like mesothelioma or sarcoma. Pericardiocentesis was performed and 1000 mL of mpericardial fluid was drained. According to these findings, surgical
resection through pericardiectomy with median sternotomy
was performed on October 2014 with pathology study. The
tumor was in the pericardial space, with irregular morphology,
size of 14×5.7x6 cm and 1500mL serohematic pericardial
fluid. Histological analysis showed spindle cells-type sarcoma,
necrosis and 18 mytosis. Immunohistochemical analysis showed
that the tumor cells were positive for bcl-2, CD99, vimentin
and the Ki-67 proliferative index was 50%; however, staining
for S100 proteins, CD34, CK AE1/AE3, EMA, enolasa, musclespecific
actin (HHF35) and desmin was negative. On the other
hand, fluorescence in situ hybridization revealed a moderate
prevalence (64%) of cells with interruption of the SYT gene
(18q11.2). Final diagnosis was monophasic synovial sarcoma
with poorly differentiated areas with unspecified margins.
Patient had a good clinical evolution but the control CT scan
three months later, showed tumor persistence, 7.5x11x2.8cm
with compression in right ventricle. The tumor grew from the
inner surface of the pericardium near the origin of the pulmonary
artery and ascending aorta with invasion of left atrium and right
coronary. The study was completed with angiography scan. The
case was evaluated in multidisciplinary committee. The specialist
decided re-intervention, but complete resection was not possible
because of the proximity and attachment to the great vessels.
In CT scan after surgery, the mass was reduced around 50%.
In multidisciplinary committee, we discussed the possibility of
adjuvant radiation therapy. Finally, patient received radiation
treatment with prescription dose of 45Gy, 1.8Gy daily (Figure
2). He didn´t had any toxicity. After three months, patient had a
new recurrence. In committee we decided not surgery, patient
received chemotherapy. Finally, patient had a new recurrence
and died in 12 months after diagnosis (Figure 3).
Pericardial Synovial Sarcoma (PSS) is a rare primary
malignant tumor of the heart and has an unclear prognosis.
Primary cardiac tumours are uncommon, occurring less
frequently than metastatic tumours with an incidence in autopsy
series ranging only from 0.001-0.03% . Most of the primary
cardiac tumours are benign and approximately 25% of them are
malignant, of which the majority are sarcomas but originating
from the pericardium are exceedingly rare accounts for
approximately 4.2% of primary cardiac sarcomas. In descending
order of frequency, these are angiosarcoma, fibrosarcoma,
rhabdomyosarcoma, and malignant fibrous histiocytoma . It
is more frequent in young adults between 15 and 35 years of age
. PSS was first described in 1978 . The signs and symptoms
caused by the primary cardiac sarcoma are extremely variable
and nonspecific. Clinical manifestations can be divided into
four categories: systemic; embolic; cardiac; and secondary to
The most common systemic manifestations are fever, chills,
fatigue, night sweats and weight loss. Embolic manifestations
occur mainly in sarcomas invading the cardiac cavities, causing
pulmonary or systemic embolism. Cardiac manifestations
depend on the location of the tumor: predominantly pericardial,
intramural or intracavitary. In the case of pericardial sarcoma, the most common initial clinical picture results from massive
hemorrhagic pericardial effusion and cardiac tamponade .
The organs most often affected by primary cardiac sarcoma
metastases are the lungs, brain and bones. The tumors are
classified into three histologic subtypes: monophasic, biphasic
and poorly differentiated . The histologic type was judged to
be monophasic in the current case. Biphasic PSS tumor composed
of spindled and epithelioid areas or as a monophasic tumor,
characterized by the spindle cell component only. Although
immunological characteristics, such as positivity for bcl-2 and
CD99, are not exclusive to synovial sarcoma, a definitive diagnosis
can be made based on the presence of the chromosomal change
t(X;18) (p11;q11), the cytogenetic hallmark of synovial sarcoma.
The SS18 gene on 18q and either the SSX1 or SSX2 gene on Xp
undergo reciprocal translocation, forming a fusion gene, SS18-
SSX, with the subsequent production of fusion proteins; more
than 90% of synovial sarcomas present with this characteristic
molecular signature. In addition, biphasic synovial sarcoma has
a SYT-SSX1 fusion transcript, whereas SYT-SSX2-positive tumors
are monophasic synovial sarcomas . It is most frequent
presenting symptom is signs of cardiac tamponade; subsequent
diagnostic imaging, including echocardiography or chest CT,
reveals a pericardial mass requiring biopsy for diagnosis .
An important survival factor is complete resection, but
it is rare. Radiotherapy and chemotherapy are indicated in
incomplete resection o to prevent locoregional recurrence.
While broad surgical resection is the first choice for treatment,
chemotherapy and radiotherapy are carried out when surgical
resection is unsuccessful; however, the prognosis of this disease
is poor . Median survival was around 15-25 months in some
Due to its extreme rarity, the most effective therapeutic
strategy for treating pericardial synovial sarcoma could not
be determined, and the complete or near total excision of the
tumor was performed in only five of the reported cases [10-13].
The pericardial tumor observed in the present case was also
considered to be unresectable, due to its strong attachment to
the visceral pericardium . Management of synovial sarcoma
of pericardial origin is challenging and needs a multimodal
approach. It is an aggressive tumor with a poor prognosis.
Most patients have a short survival time. One exception is the
case report of a patient whose survival exceeded 14 years and
involved recurrences and multiple surgical resections. Surgical
resection can lead to curative therapy. Most often, due to the site
of origin, tumors are adherent to adjacent vital organs and are
non-resectable at the time of diagnosis. Therefore, EBRT and
less commonly neo-adjuvant chemotherapy are used to make the
tumor resectable [14-18]. In our patient, we could not attempt
complete surgical resection. Therefore, after the initial biopsy
and pericardial window, neo-adjuvant chemotherapy was done
with six cycles of high dose ifosfamide (2000mg/m2) and mesna.
Due to the rarity of these tumors, it is very difficult to establish an
optimal regimen for chemotherapy. In general, synovial sarcomas
are chemo-sensitive to ifosfamide and show a good response. A
case series of 13 patients with synovial sarcoma treated with
high-dose ifosfamide showed a response in all patients, with
4 clinical remissions achieved. Combining doxorubicin with
ifosfamide may achieve a higher response rate (58%) but patient
tolerability and side effects need to be considered [19-21]. The
initial favorable response to neoadjuvant high dose ifosfamide
in our patient made the tumor respectable and may be a viable
alternative to EBRT alone in non-respectable tumors .
EBRT is a very useful modality of treatment post-surgery
when the margins of resection are positive. In our patient, EBRT
was initiated one month after surgery. Previous reports have
shown similar favorable results. To the authors’ knowledge
only EBRT has been employed in previous cases. Intraoperative
Radiation Therapy (IORT) with a radiation dose of 15-45 Gray
appeared to be useful for local control and to be more effective
in patients without distant metastases at the first visit in a study
that included 24 patients with soft tissue sarcomas (1 case of
synovial sarcoma) [22-24]. Close monitoring for recurrence
is very crucial in management of this tumor. CT or magnetic
resonance imaging should be performed every 6 months to
detect subclinical recurrences. We performed CT imaging every
three months along with regular clinical follow-up or symptoms.
Repeat imaging is essential to be able to diagnose subclinical
recurrence and initiate repeat broad surgical resection and
follow-up chemotherapy if needed. We used the anti-mitotic
agent phosphamide for treating the recurrence .
Cardiac transplant had been an alternative in some cases
with more survival, but it is controversial due to tumoral etiology.
This report described one case of pericardial synovial
sarcoma, an extremely rare primary cardiac tumor, despite
proper treatment, has an unclear prognosis  (Table 1).