SYT–SSX fusion genes in synovial sarcoma of the thorax

Exploring the Relationship between Fusion Genes and MicroRNAs in Cancer

Fusion genes are key cancer driver genes that can be used as potential drug targets in precision therapies, and they can also serve as accurate diagnostic and prognostic biomarkers. The fusion genes can cause microRNA (miRNA/miR) aberrations in many types of cancer. Nevertheless, whether fusion genes incite miRNA aberrations as one of their many critical oncogenic functionalities for driving carcinogenesis needs further investigation. Recent discoveries of miRNA genes that are present within the regions of genomic rearrangements that initiate fusion gene-based intronic miRNA dysregulation have brought the fusion genes into the limelight and revealed their unexplored potential in the field of cancer biology. Fusion gene-based 'promoter-switch' event aberrantly activate the miRNA-related upstream regulatory signals, while fusion-based coding region alterations disrupt the original miRNA coding loci. Fusion genes can potentially regulate the miRNA aberrations regardless of the protein-coding capability of the resultant fusion transcript. Studies on out-of-frame fusion and nonrecurrent fusion genes that cause miRNA dysregulation have attracted the attention of researchers on fusion genes from an oncological perspective and therefore could have potential implications in cancer therapies. This review will provide insights into the role of fusion genes and miRNAs, and their possible interrelationships in cancer.

Modified autotransplantation technique for surgical resection of complex pericardial synovial sarcoma

Technical details for complex cardiac tumor resection are sparse. We describe the operative technique of modified autotransplantation for resection of a complex pericardial synovial sarcoma in a 63-year-old, Caucasian female. Surgical exposure demonstrated tumor origin at the superior cavoatrial junction and invasion of the aorta, main pulmonary artery, superior pulmonary veins, and left atrial roof. Full macroscopic surgical resection was achieved. The patient received adjuvant radiation for microscopic positive margins and remains alive and with no tumor progression at one year postoperatively. We conclude that modified autotransplantation is a challenging but effective surgical technique when performed with careful patient selection and availability of skilled, cardiothoracic surgeons at a cardiac center of excellence.

Emerging oncogenic fusions other than ALK, ROS1, RET, and NTRK in NSCLC and the role of fusions as resistance mechanisms to targeted therapy

Recent evidence has shown that gene fusions caused by chromosomal rearrangements are frequent events in the initiation and during progression of solid tumors, including non-small cell lung cancers (NSCLCs). Since the discoveries of ALK and ROS1 fusions in 2007 and the subsequent successes of pharmacological targeting for these fusions, numerous efforts have identified additional oncogenic driver fusions in NSCLCs, especially in lung adenocarcinomas. In this review, we will summarize recent advances in this field focusing on novel oncogenic fusions other than ALK, ROS1, NTRK, and RET fusions, which are summarized in other articles in this thematic issue. These novel gene fusions include neuregulin-1 (NRG1) fusions, MET fusions, fusion genes involving fibroblast growth factor receptor (FGFR) family members, EGFR fusions, and other rare fusions. In addition, evidence has suggested that acquisition of gene fusions by cancer cells can be a molecular mechanism of acquired resistance to targeted therapies. Most of the current data are from analyses of resistance mechanisms to EGFR tyrosine kinase inhibitors in lung cancers with oncogenic EGFR mutations. However, a few recent studies suggest that gene fusions can also be a resistance mechanism to ALK-tyrosine kinase inhibitors in lung cancers with oncogenic ALK fusions. Detection, validation, and pharmacological inhibition of these fusion genes are becoming more important in the treatment of NSCLC patients.

Rare monophasic mediastinal pleural synovial sarcoma diagnosed via endobronchial ultrasound-transbronchial needle aspiration

The mediastinum is a rare site for occurrence of a primary synovial sarcoma (SS) with very few cases reported in the literature. The diagnosis so far has been achieved mainly via open surgery, with only three reported cases diagnosed via endobronchial ultrasound with transbronchial needle aspiration (EBUS-TBNA), however, none of those were located at the posterior mediastinum, without showing any oesophageal or endobronchial involvement. To our knowledge, this is the first reported case of a monophasic primary pleural mediastinal SS purely involving the posterior mediastinum without oesophageal or endobronchial component, diagnosed via EBUS-TBNA.

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

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.

Primary cardiac synovial sarcoma: A review correlating outcomes with surgery and adjuvant therapy

BACKGROUND

Cardiac synovial sarcoma (CSS) is an extremely rare malignant tumor with a severe prognosis, due to frequent relapses and metastases. To obtain useful information for treatment protocols, we analyzed survival and therapy data from the cases reported in the literature.

METHODS

A search of MEDLINE was performed throughout December 2018. Using key words relating to primary CSS, we collected from the literature a total of 97 cases, mainly consisting of single case reports. To identify predictors of overall survival, statistical analyses were performed on a selected cohort of 55 patients for whom relevant clinicopathological data were available, including surgery and adjuvant therapy.

RESULTS

The univariable analysis revealed that patients in their first three decades of life have better overall survival. The univariable analysis also showed that patients not receiving adjuvant chemotherapy are at increased risk of death. In the multivariable analysis, tumor resection and chemotherapy are factors significantly improving overall survival.

CONCLUSION

The survival of patients with CSS is positively influenced by a young patient's age and greatly improved by the administration of chemotherapy, even in the absence of tumor resection.

Pericardial synovial sarcoma: challenges in diagnosis and management

Introduction: Pericardial synovial sarcoma is an extremely rare tumor with poor prognosis. Timely diagnosis and aggressive multimodal management improves patient outcome. We present our experience of diagnosis and management of a young patient with monophasic synovial sarcoma arising from pericardium.

Case: A 27-year-old man presented with dyspnea and cough of three weeks duration. Examination revealed sinus tachycardia, distant heart sounds and elevated jugular venous pressure. Chest X-ray showed widened mediastinum. Transthoracic echocardiogram (TTE) noted large pericardial effusion with tamponade physiology. Therapeutic pericardiocentesis yielded hemorrhagic fluid. Computed tomography (CT) of the chest showed persistent pericardial effusion and a left anterior mediastinal mass. Left anterior thoracotomy, pericardial window and left anterior mediastinotomy were done, revealing a well-encapsulated gelatinous tumor originating from the pericardium. Histology and immunohistochemical profile showed the tumor to be a monophasic synovial sarcoma. Fluorescent in-situ hybridization (FISH) was positive for SS18 (SYT) gene rearrangement on chromosome 18q11, substantiating the diagnosis. Work-up for metastases was negative. Neo-adjuvant chemotherapy with high dose ifosfamide led to substantial reduction in the size of the tumor. The patient underwent surgical resection and external beam radiation therapy (EBRT) post surgery. He had symptom-free survival for 8 months prior to local recurrence. This was managed with left lung upper lobectomy and follow-up chemotherapy with docetaxel. The patient is currently stable with an acceptable functional status.

Conclusion: In patients with pericardial effusions of unknown etiology, multiple modalities of cardiac imaging must be employed if there is suspicion of a pericardial mass. CT and magnetic resonance imaging (MRI) are useful to evaluate for pericardial thickening or masses in addition to TTE. Treatment of synovial sarcoma is not well established. Surgery is the cornerstone of treatment. In non-resectable tumors, aggressive neo-adjuvant chemotherapy with ifosfamide followed by surgical resection and EBRT may lead to improved outcome.

A patient with primary pericardial synovial sarcoma who presented with cardiac tamponade: a case report and review of the literature

A 36-year-old man presented with near-syncope. He was found to have massive pericardial effusion with a giant pericardial tumorous lesion. The pericardial effusion exhibited a bloody nature; however, neither malignant cells nor infectious organisms were detected. (18)F-fluorodeoxyglucose-positron emission tomography (FDG-PET) showed an increased uptake of FDG in the pericardial tumor only. Although the tumor was not resectable, thoracotomy and tissue sampling were performed. A histological analysis showed CD99 positivity and SYT gene rearrangement, leading to a diagnosis of synovial sarcoma arising from the left lateral pericardial surface. The patient is now receiving chemotherapy.

Primary cardiac synovial sarcoma

Primary cardiac synovial sarcoma is an extremely rare entity. The clinical and pathologic characteristics are still poorly understood, and prognostic factors influencing overall survival are still unknown. In the present study, all characteristics of reported patients, including sex, age, clinical presentations, laboratory tests, electrocardiogram, imaging findings, pathology, location, therapy, and follow-up were carefully reviewed and survival analysis was performed. The present study has summarized some key features and may provide an effective consultation for the diagnosis and treatment of the tumor.

Synovial sarcoma of the spine: A report of three cases and review of the literature

Background:

Synovial sarcoma (SS) is a rare sarcoma with distinct morphologic and genetic features, which, despite its name, does not arise from synovium. While most SSs (>80%) arise in the deep soft tissue of the extremities, up to 5% of these tumors are encountered in the body axis including the spine, mediastinum, retroperitoneum, and head/neck regions. Reports of SS located within the spinal axis have been rare to date.

Materials and Methods:

We searched the medical records at our institution and found three patients who were diagnosed and treated for SSs involving the spine. We also performed an exhaustive literature search using PubMed to identify all reported cases in the literature.

Results:

In this study, we report on three SS cases involving the spine. All three cases involved the paraspinal muscles and spinal nerve roots, with one case having a significant leptomeningeal involvement. In two cases, “smaller operations” were performed first because the lesions were thought to be benign, however, when the final pathology identified them as SSs, more radical procedures were performed. Additionally, we identified 14 cases of SSs involving the spine published in the literature and all cases are reviewed here.

Conclusions:

Due to limited numbers of cases, spine SS long-term outcomes are hard to quantify. The currently accepted standard of treatment for SSs starts with wide surgical excision with negative margins followed by chemotherapy and radiation. We summarize the available literature on spinal SSs and review the current treatment options available for these tumors.

Primary pericardial synovial sarcoma confirmed by molecular genetic studies: a case report

Primary pericardial synovial sarcoma is an extremely rare tumor. The awkward tumor site and clinical features associated with quite advanced disease at presentation make obtaining adequate biopsy material challenging. Ambiguous histologic features may also make diagnosis difficult. We present a case of a 15-year-old patient with an original diagnosis of a spindle cell thymoma. After definitive surgery the diagnosis was amended to a primary pericardial synovial sarcoma. Molecular confirmation of the SYT-SSX fusion gene was critical in reaching an accurate diagnosis. This highlights the necessity for routine molecular genetic studies, so that patient therapy can be directed accordingly.

Diagnostik des Synovialsarkoms

Synovial sarcoma diagnosis and differential diagnostic distinction from other spindle cell sarcomas may be difficult. In these cases the detection of the t(X;18) translocation by FISH and RT-PCR is diagnostically extremely helpful. This study was aimed at the question whether or not simultaneous use of both methods is required for evidence of t(X;18) translocation.Paraffin-embedded tumour specimens from 53 patients were included in the study which were considered to be possible synovial sarcomas on the basis of histological aspect and immunohistochemical profile. Detection of t(X;18) was performed using FISH and RT-PCR simultaneously. Nuclei and amplifiable RNA could be isolated from 39 of the 53 included cases (75%). In 72% of these 39 cases FISH and RT-PCR showed identical negative or positive results. The remainder of the cases (28%) showed either a typical PCR product or a positive FISH signal.In conclusions FISH could be confirmed by typical PCR products and is therefore qualified as an internal quality control. Nevertheless tumour biological and methodical reasons have an important influence on both methods. Consequently in difficult cases simultaneous FISH and RT-PCR analysis is necessary for a clear evidence of t(X;18) translocation.