|Year : 2015 | Volume
| Issue : 2 | Page : 62-64
Primary synovial cell sarcoma of the heart: A rare case
Anil Sharma, Sunil Dixit, Mohit Sharma, Neeraj Sharma, Omeshwar Sharma
Department of Cardio-Vascular and Thoracic Surgery, Sawai ManSingh Medical College, Jaipur, Rajasthan, India
|Date of Web Publication||23-Jun-2015|
Dr. Mohit Sharma
Department of Cardio-Vascular and Thoracic Surgery, Sawai ManSingh Medical College, Jaipur, Rajasthan - 302 004
Source of Support: None, Conflict of Interest: None
| Abstract|| |
A synovial sarcoma (also known as malignant synovioma) is a rare form of cancer that usually occurs near the joints of the arm, neck, or leg. It is one of the soft tissue sarcomas. Primary cardiac neoplasms are rare. Most common site for synovial sarcoma is lower limb. Synovial sarcoma of the heart is extremely rare. Occurrence of synovial sarcoma at extra synovial site is very uncommon. It is two times common in right side heart than left side so left side synovial sarcoma is rarest of rare, only very limited cases are reported. Here, we report a case of primary synovial cell sarcoma of the left side of the heart in a 26-year-old female. She presented with dyspnea and weakness only. She was operated for left-sided mass covering mitral valve; further histo-pathology revealed the mass as synovial cell sarcoma. In Indian scenario, this type of rare case needs documentation.
Keywords: Cardiac tumor, malignancies, synovial cell sarcoma
|How to cite this article:|
Sharma A, Dixit S, Sharma M, Sharma N, Sharma O. Primary synovial cell sarcoma of the heart: A rare case. Heart Views 2015;16:62-4
| Case Report|| |
A 26-year-old female was presented with the history of dyspnea and giddiness since 1 month. There was no history of palpitation, chest pain, and constitutional symptoms. Two-dimensional echo revealed that there was a left atrial (LA) mass and severe mitral stenosis (Mitral Valve Area-0.5 cm2) with normal ejection fraction. Provisional diagnosis was LA myxoma.
Patient was taken for surgery, after establishing full flow on cardio-pulmonary bypass machine left atrium was opened. There was LA mass of about 7 cm × 5 cm attached to posterior mitral leaflet annulus and beyond annulus extending in left atrial appendage (LAA) obstructing mitral valve [Figure 1]. Complete excision of the tumor was not possible, so the tumor was removed without sacrificing the mitral valve. The patient had uneventful post-operative recovery.
Histo-pathological examination [Figure 2] revealed that the tumor was highly cellular and composed of sheets and bundles of pleomorphic spindle-shaped cells admixed with round and polygonal cellular areas showing markedly pleomorphic nuclei with predominant nucleoli and indistinct borders. At some places, the neoplastic cells were arranged concentrically around blood vessels. Large area of necrosis, myxoid changes, and focal infiltration was also present. The mitotic activity was very high (3-5/hpf). On immunohistochemistry, the cells were immunopositive for cytokeratin, viamentin, mic-2, and bcl-2. There was focal immune reactivity for CD 34 and calretenin; the cells were immunonagetive for CD 31. Post-operative chest and abdominal computed tomography (CT) study were normal.
Patient was referred to oncology department for further chemo-radiotherapy. After 1 month patient attended the pain clinic with complaints of pain and weakness over lower back and both lower limbs. Magnetic resonance imaging dorso-lumbar spine showed metastasis to D 8 and L 2 vertebral bodies.
| Discussion|| |
Primary tumors of the heart are uncommon. They are usually benign and majority being myxoma only 25% are malignant. Most common are angiosarcoma 31%, rhabdomyosarcoma 21%, malignant mesothelioma 15%, and fibrosarcoma 11%. Synovial sarcoma is extremely rare 0.1%  Right side synovial sarcoma is twice more common than left side  Most common primary site for synovial sarcoma is lower limbs; occurrence outside the synovial line space is rare. This may also to occur in abdominal wall, neck, head, mediastinum, lung, and pleura. 
The clinical presentation of cardiac synovial sarcoma is non-specific, so the diagnosis is almost always at advanced stage in most of the cases. Patients usually present with more than one symptom such as shortness of breath, dyspnea, chest pain, and weight loss. Patient of left-sided tumor presents earlier than right-sided tumor due to their mass effect and obstruction to pulmonary veins  The mean age of presentation of the cardiac synovial sarcoma is 32.5 year with a range from 13 to 66 years. 
On macroscopic examination the size of tumor varies from 2.9 to 15 cm. Left-sided tumors are comparatively small  Cardiac synovial sarcoma have same morphological spectrum as there soft tissue counterparts have, which may be biphasic or monophasic. The classical biphasic synovial sarcoma has epithelial and spindles cell components admixed in varying proportion. The classical monophasic variant contains only spindle cell component arranged in similar pattern as seen in fibrosarcoma. 
For diagnosis immunohistochemical staining for both mesenchymal and epithelial markers and molecular testing for specific mutation is gold standard.  Expression of both cytokeratins and viamentin is seen in most synovial sarcoma with biphasic histology with cytokeratin and viamentin and epithelial and mesenchymal components . In monophasic synovial sarcoma, tumor cells diffusely stain for viamentin and variably positive for epithelial proteins in cells that do not appear epithelial on hematoxylin eosin staining. 
Molecular genetics studies have shown a balanced reciprocal translocation t (X; 18) (P11.2; q11.2) between SYT gene on chromosome 18 and SSX1 or SSX2 gene on chromosome X; this translocation is specific cytogenetic abnormality that occur consistently in synovial sarcoma (monophasic and biphasic).  Complex karyotype has also been reported and may have prognostic significance. Some cases have demonstrated presence of chromosomal abnormality that include t (X; 18)(p1;p1) X2, del (1) t (1;8)(q10;q10), del-(4),-13,-14,-16,+17,+18,+4,+7,+8 and del (13;15)(q10;q10).  Cases of synovial sarcoma with complex karyotype have a greater tendency to metastasize. 
All the three modality of treatment surgery, chemotherapy and radio therapy are given to patient, but surgery is main stay of treatment and wide excision of tumor is required for better outcome although it is anatomically difficult to obtain large tumor-free margins in the heart . Prognosis of synovial sarcoma is poor with most of patients dying within 1 year, and common cause of death is local recurrence.  Because synovial sarcomas are rare, so prognostic factors are hard to ascertain but younger age at diagnosis, absence of chromosomal abnormalities and origin of tumor from pericardium seems to favorable factors. 
| Conclusion|| |
Although cardiac synovial tumors are extremely rare tumors, they should be kept in differential diagnosis with myxoma, mesothelioma, and fibrosarcoma.  Intra-operative frozen section should be done, but careful sectioning immunohistochemistry and molecular genetics studies are the key for correct diagnosis and better treatment outcome.
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[Figure 1], [Figure 2]