Pericardial Synovial Sarcoma: Case Report, Literature Review and Pooled Analysis

Abstract

Background: Pericardial synovial sarcomas (PSS) are very rare tumors, with dismal prognosis and limited data. We describe the clinical features and identify prognostic factors of primary PSS.

Case report: We describe the case of a 56-year-old male patient with PSS managed by the multidisciplinary team of thoracic oncology. The therapeutic plan comprised surgery, chemotherapy, stereotactic radiosurgery and targeted therapy, with excellent results.

Materials and methods: Data from 37 cases reported in English during the past 20 years were gathered and analyzed. PSS was found to occur at a mean age of 36±17.082 (range=13-67) years. Survival analysis was performed on 20 cases with follow-up of at least 6 months.

Conclusion: Only complete resection of the tumor seems to be an independent prognostic factor. To our knowledge, this is the first report on the safety and effectivity of pazopanib in PSS and may provide guidance for similar cases in the future.

Keywords: Pericardial synovial sarcoma; chemotherapy; pazopanib; stereotactic radiosurgery.

Figure 1. Serial images of pericardial sarcoma according to applied therapies. A: Magnetic resonance imaging (MRI) study of the thorax, T2- weighted imaging (T2WI) axial image, at diagnosis, showing an inhomogeneous hyperintense lesion of the mediastinum among the aorta, pulmonary artery, main bronchi and superior vena cava (arrows) B: T2WI axial image at the same level after the fourth chemotherapy session, showing decrease in the size of the lesion. C: Follow-up with positron-emission tomography 3 months later indicated stability of the lesion size with mild hypermetabolic activity (maximum standard uptake value: 3.1) D: T2WI MRI study at the same level after Cyber Knife radiosurgery with further decrease of the size and signal intensity of the tumor. E: Follow-up MRI study T2WI after 5 months of therapy with tyrosine kinase inhibitor pazopanib (Votrient) indicated a further slight decrease of the tumor size. F: Follow-up computed tomography at the same level 4 months later, during therapy with Votrient, showing stability of the tumor size (arrow heads).

Figure 2. Microscopically, a biphasic morphological pattern was noted for our case, with both an epithelioid (A) as well as a spindle (B) cell component (hematoxylin and eosin). Tumor cells showed immunopositivity for cytokeratins AE1/AE3 (C), CD99 (D), transducin-like enhancer of split 1 (E) and BCL2 (F). Magnification ×20.