Translocation X;18 in synovial sarcoma

Small gastric synovial sarcoma diagnosed and treatment by laparoscopic-endoscopic cooperative surgery: a case report

We report a case of small gastric synovial sarcoma (SS) finally diagnosed after laparoscopic-endoscopic cooperative surgery (LECS). A 50 year-old male underwent medical examination for a chief complaint of epigastric pain. Endoscopic examination showed a 20 mm submucosal tumor (SMT) located in the anterior wall which extended to the lesser curvature of the middle stomach. The biopsy tissue did not yield a definitive diagnosis. During 6 months of follow-up for this lesion suspected to be an inflammatory tumor, neither the shape nor the size of the tumor changed. We performed LECS for both diagnosis and treatment. Histologically, the tumor was composed of fascicles of spindle cells. Immunohistochemically, the tumor cells were focally positive for epithelial membrane antigen, cytokeratin (AE1/AE3) and S100 protein, while being negative for desmin, α-smooth muscle actin, CD34, c-kit and DOG1. The expression of INI1 was reduced. Fluorescence in situ hybridization (FISH) detected SS18 rearrangement. The SMT was diagnosed as primary SS. A SMT measuring < 20 mm might be malignant potential tumor such as SS even if there are no typical malignant findings by endoscopy. Surgical resection should be considered for SMT measuring < 20 mm with atypical findings even in the absence of definitive high-risk features.

The potential pitfalls of synovial sarcoma mimicking intraneural ganglion cyst: A case report and literature review

INTRODUCTION AND IMPORTANCE

Synovial sarcoma is a rare soft tissue sarcoma (STS) that accounts for 5-10 % of all STS. Synovial sarcoma of the peripheral nerve is very rare, with only 26 cases reported in the literature. Hence, this case report describes an unusual presentation of synovial sarcoma mimicking intraneural ganglion cysts and a literature review.

PRESENTATION OF CASE

We describe a 36-year-old female who presented to our clinic complaining of left leg pain for six years. MRI was done, which revealed a cystic lesion. With an impression of intraneural ganglion cyst versus nerve sheath tumor of the common peroneal nerve. The patient underwent exploration surgery and mass excision. The mass was sent for histopathology following excision, where the results indicated monophasic synovial sarcoma. An additional surgery, an epineurectomy of the common peroneal nerve and tumor bed excision, was followed by adjuvant chemotherapy with a Doxorubicin-based regimen. Following surgery, our patient's neurological symptoms improved.

CLINICAL DISCUSSION

The mainstay of treatment in synovial sarcoma is surgical excision with a Doxorubicin-based regimen of chemotherapy and/or radiotherapy based on tumor characteristics. Tumors smaller than 5 cm in MRI usually show homogenous enhancement and can be mistaken for benign tumors. Hence, a biopsy should be done before surgery to avoid misdiagnosis.

CONCLUSION

Even though it is extremely rare, synovial sarcoma of the lower extremity should be considered when a painful swelling of the lower leg is associated with a long duration of symptoms. Such lesions are best managed by surgical excision and postoperative chemotherapy.

Use of Fluorescence In Situ Hybridization (FISH) in Diagnosis and Tailored Therapies in Solid Tumors

Fluorescence in situ hybridization (FISH) is a standard technique used in routine diagnostics of genetic aberrations. Thanks to simple FISH procedure is possible to recognize tumor-specific abnormality. Its applications are limited to designed probe type. Gene rearrangements e.g., ALK, ROS1 reflecting numerous translocational partners, deletions of critical regions e.g., 1p and 19q, gene fusions e.g., COL1A1-PDGFB, genomic imbalances e.g., 6p, 6q, 11q and amplifications e.g., HER2 are targets in personalized oncology. Confirmation of genetic marker is frequently a direct indication to start specific, targeted treatment. In other cases, detected aberration helps pathologists to better distinguish soft tissue sarcomas, or to state a final diagnosis. Our main goal is to show that applying FISH to formalin-fixed paraffin-embedded tissue sample (FFPE) enables assessing genomic status in the population of cells deriving from a primary tumor or metastasis. Although many more sophisticated techniques are available, like Real-Time PCR or new generation sequencing, FISH remains a commonly used method in many genetic laboratories.

Synovial Sarcoma of the Nerve-Clinical and Pathological Features: Case Series and Systematic Review

BACKGROUND

Synovial sarcoma of the nerve is a rare entity with several cases and case series reported in the literature. Despite an improved understanding of the biology, the clinical course is difficult to predict.

OBJECTIVE

To compile a series of patients with synovial sarcoma of the peripheral nerve (SSPN) and assess clinical and pathological factors and their contribution to survival and recurrence.

METHODS

Cases from 2 institutions collected in patients undergoing surgical intervention for SSPN. Systematic review including PubMed and Scopus databases were searched for related articles published from 1970 to December 2018. Eligibility criteria: (1) case reports or case series reporting on SSPN, (2) clinical course and/or pathological features of the tumor reported, and (3) articles published in English.

RESULTS

From patients treated at our institutions (13) the average follow-up period was 3.2 yr. Tumor recurrence was seen in 4 cases and death in 3. Systematic review of the literature yielded 44 additional cases with an average follow-up period of 3.6 yr. From pooled data, there were 10 recurrences and 7 deaths (20% and 14%, respectively). Adjuvant treatment used in 62.5% of cases. Immunohistochemical markers used in diagnosis varied widely; the most common are the following: Epithelial membrane antigen (EMA), cytokeratin, vimentin, cluster of differentiation (CD34), and transducin-like enhancer of split 1 (TLE1). Statistical analysis illustrated tumor size and use of chemotherapy to be negative predictors of survival. No other factors, clinically or from pathologist review, were correlated with recurrence or survival.

CONCLUSION

By combining cases from our institution with historical data and performing statistical analysis we show correlation between tumor size and death.

Uncommon tumors of temporomandibular joint: An institutional experience and review

BACKGROUND

The temporomandibular joint (TMJ) harbors a myriad of pathologic alterations including arthritides and benign and malignant neoplasms.

METHODS

Herein, we describe our institutional experience of some uncommon and unusual synovial pathologies of the TMJ along with a review of literature. We searched through the archives of department of pathology and institutional electronic medical record for specimens of TMJ between 1999 and 2019. Hematoxylin and eosin slides were reviewed and data (final diagnosis, age, gender, clinical presentation, tumor size, treatment modality, recurrence, and vital status) were collected.

RESULTS

A total of seven cases were identified including four cases of synovial chrondromatosis; and one case each of tenosynovial giant cell tumor, localized type, tenosynovial giant cell tumor, diffuse type, and synovial sarcoma.

CONCLUSIONS

The article emphasizes on the clinical, radiologic, pathologic, and molecular features of these uncommon entities. The differential diagnosis of each entity is also discussed. Current updates in the management are also reviewed.

[Pathological and molecular features of malignancies underlined by BAF complexes inactivation]

BAF complexes are chromatin remodelling complexes made up of 15 subunits which overview transcription regulation. A subset of their subunits are notoriously linked to cancer, with the examples of SMARCB1, SMARCA4, ARID1A/1B and PBRM1. The complexes act as tumor suppressor genes, commonly mutated in a wide array of malignancies with an overrepresentation of sarcomas and tumors of the central nervous system. The recurrent inactivation of their genes points towards their driving role in the tumorigenesis of SMARCB1 in malignant rhabdoid tumors and SMARCA4 in small cell carcinoma of the ovary, hypercalcemic type. These tumors are morphologically similar composed of solid sheets of cells displaying vesicular nuclei dotted with clear chromatin and conspicuous nucleoli. Genomically, they share simple diploid profiles with no other alterations than in the culprit gene. Other mesenchymal tumors, distinct from malignant rhabdoid tumors are associated with BAF alterations, namely epithelioid sarcomas, SMARCA4-deficient thoracic sarcomas. BAF subunits are mostly inactivated through mutations or deletions but also occur through translocations in medullary carcinoma of the kidney and synovial sarcomas. Apart from tumors displaying recurrent alterations of the complexes, some variants or tumor variants display BAF alterations, including epithelioid malignant peripheral nerve sheet tumors and poorly differentiated chordomas. Lastly, some malignancies display low frequency of BAF alterations, in keeping with their passenger role in tumorigenesis with the example of dedifferentiated carcinomas, especially in colon, lung and uterus. BAF complexes alterations correlate with morphological features recognizable by microscopy, paving the way for their routine diagnosis and potential therapeutic prospects.

Canonical Wnt/β-catenin signaling activation in soft-tissue sarcomas: A comparative study of synovial sarcoma and leiomyosarcoma

Background:

Previous studies have shown that aberrant activation of the Wnt/β-catenin pathway is associated with many malignant neoplasms. This includes some soft-tissue sarcoma phenotypes, most notably synovial sarcoma, implicating potential targets for novel molecular therapies.

Objective:

We investigate the level of Wnt/β-catenin pathway activation present in leiomyosarcomas relative to synovial sarcomas, using expression of LEF1 and β-catenin as surrogates.

Methods:

Cancer outlier profile analysis was performed on messenger RNA expression datasets in Oncomine (70 synovial sarcomas, 178 leiomyosarcomas). Results for LEF1 and β-catenin messenger RNA expression were reported in terms of median-centered intensity. Separate immunohistochemical studies were performed on tissue microarrays created from 77 synovial sarcomas and 89 leiomyosarcomas using antibodies to LEF1 and β-catenin. Tumors with unequivocal strong nuclear staining involving ⩾5% of cells were interpreted as positive.

Results:

Cancer outlier profile analysis demonstrated a higher level of LEF1 messenger RNA expression in synovial sarcomas than in leiomyosarcomas (p < 0.0001), but showed no significant difference in β-catenin messenger RNA expression (p = 0.868). Immunohistochemistry showed most synovial sarcomas had strong nuclear expression of LEF1 (79%) and β-catenin (84%), while a small minority of leiomyosarcomas had strong nuclear expression of LEF1 (5%) and β-catenin (6%).

Conclusion:

These results provide further evidence that aberrant activation of the Wnt/β-catenin pathway is present in most synovial sarcomas, but not in most leiomyosarcomas. While targeting the constituents of this pathway might be effective in the treatment of synovial sarcomas, it is not likely to be an effective strategy in the treatment of leiomyosarcomas.

Factors Associated With Survival in Patients With Synovial Cell Sarcoma of the Head and Neck: An Analysis of 167 Cases Using the SEER (Surveillance, Epidemiology, and End Results) Database

IMPORTANCE

Synovial cell sarcoma of the head and neck (SCSHN) is a rare tumor associated with significant morbidity and mortality. The literature regarding these tumors is limited to case series and case reports. We used data from the population-based US Surveillance, Epidemiology, and End Results (SEER) cancer registry to determine factors affecting both overall survival and disease-specific survival of patients with SCSHN.

OBJECTIVE

To determine the clinicopathologic and therapeutic factors determining survival in patients with SCSHN.

DESIGN, SETTING, AND PARTICIPANTS

The SEER registry was reviewed for patients with primary SCSHN from January 1, 1973, to January 1, 2011.

MAIN OUTCOMES AND MEASURES

Overall survival (OS) and disease-specific survival.

RESULTS

A total of 167 cases of SCSHN were identified. The mean (SD) age at diagnosis was 37.9 (17.3) years, and 100 (59.9%) of the patients were males. The monophasic spindle cell and biphasic variants were the most common histologic subtypes. Surgical resection and radiotherapy were performed in 150 (89.8%) and 108 (64.7%) of the cases, respectively. The median OS at 2, 5, and 10 years was 77%, 66%, and 53%, respectively. Univariate Kaplan-Meier survival analysis revealed that age, race, and tumor stage and size were associated with improved survival. Histologic subtype was not associated with significant differences in survival. Radiotherapy was associated with improved disease-specific survival (hazard ratio [HR], 0.29 [95% CI, 0.12-0.68]; P = .003), but surgical management was not associated with improved survival (HR, 0.52 [95% CI, 0.19-1.46]; P = .21). Multivariate Cox regression analysis revealed that size greater than 5 cm (adjusted HR, 3.60 [95% CI, 1.43-9.08]; P = .007) and stage at presentation (adjusted HR, 3.86 [95% CI, 2.01-7.44]; P < .001) were independent determinants of OS. In separate analysis of cohorts with tumors 5 cm or less and larger than 5 cm, stage at presentation was found to be a significant indicator of the probability of survival in both cohorts (adjusted HR, 3.10 [95% CI, 1.46-6.60]; P = .003 and 5.32 [95% CI, 1.49-18.98]; P = .01, respectively); surgical resection and radiotherapy were not associated with differential survival outcomes using this model.

CONCLUSIONS AND RELEVANCE

Synovial cell sarcoma of the head and neck is rare. Independent significant determinants of survival include size (>5 cm) and stage at presentation. Histologic subtype of the tumor is not a significant indicator of the probability of survival. Surgical resection and radiotherapy were not independent determinants of survival.

A clinicopathologic study on SS18 fusion positive head and neck synovial sarcomas

OBJECTIVE

To determine clinicopathologic factors on survival in patients with head and neck synovial sarcoma.

PATIENTS AND METHODS

We retrospectively identified patients with molecularly confirmed synovial sarcomas of the head and neck (SS-HN), either by the presence of SS18-SSX fusion transcript by RT-PCR or SS18 gene rearrangement by FISH, who were managed at our institution over a 20-year period (1996-2015). Kaplan-Meier survival analysis and log-rank test were performed to evaluate variables related to disease specific survival (DSS). Fisher exact test was performed to evaluate variables related to local recurrence.

RESULTS

Thirty-four patients (20 males and 14 females, mean of 31years) with SS18-SSX fusion-positive SS-HN were identified. The parapharyngeal region of the neck was the most common site. The mean tumor size was 4.8cm (0.8-10cm). Two-thirds (n=23) of cases had a monophasic histology. The 2, 5 and 10-year DSS rates were 97%, 79% and 68%. The 5-year DSS rates for the adult/pediatric cohort were 74%/88%. Recurrence showed significant effect on DSS (p=0.021). There was no significant effect on DSS with age, therapy modality, tumor site, surgical margin, tumor size (⩽5cm vs. >5cm) and histopathologic subtype. Tumor site (i.e. skull base/paranasal sinus region) was associated with local recurrence (p=0.003).

CONCLUSION

In our cohort DSS rate was associated with recurrence. Tumors located in the skull base/paranasal sinus region were associated with a higher rate of local recurrence. Thus appropriate selection of high risk patients who can benefit from multimodality therapies might improve survival.

The diagnostic utility of reduced immunohistochemical expression of SMARCB1 in synovial sarcomas: a validation study

Synovial sarcoma is a malignant mesenchymal neoplasm of uncertain histogenesis, characterized by a specific SS18-SSX fusion. The diagnosis of synovial sarcoma can be challenging based on morphology and conventional immunohistochemistry alone, and identification of the fusion gene by molecular genetics may be necessary for diagnosis. Several recent studies have demonstrated the diagnostic utility of the reduced expression of SMARCB1 in synovial sarcomas as measured using immunohistochemistry. Therefore, we undertook a validation study using synovial sarcomas and other spindle or round cell tumors that could enter differential diagnosis of monophasic or poorly differentiated synovial sarcomas. Among 36 synovial sarcomas that were successfully evaluated, the expression of SMARCB1 was diffusely reduced in 33 cases (92%) at variable degrees. In contrast, the expression of SMARCB1 was not reduced in any of the 93 evaluable non-synovial sarcoma tumors (5 thymomas, 5 sarcomatoid mesotheliomas, 10 schwannomas, 9 mesenchymal chondrosarcomas, 20 solitary fibrous tumors, 19 Ewing sarcomas, and 25 malignant peripheral nerve sheath tumors). A few schwannomas and malignant peripheral nerve sheath tumors showed mosaic or complete loss of SMARCB1 expression. Reduced expression of SMARCB1 immunoreactivity was therefore found to be highly sensitive and specific for synovial sarcoma, and can be useful for rapidly and accurately confirming the diagnosis of synovial sarcoma. This reduction in SMARCB1 expression likely reflects the BAF47 ejection mechanism of the SS18-SSX fusion product and can therefore be viewed as an indirect visualization of this fusion product.

Investigation of IGF2, Hedgehog and fusion gene expression profiles in pediatric sarcomas

The childhood sarcomas are malignant tumors with high mortality rates. They are divided into two genetic categories: a category without distinct pattern karyotypic changes and the other category showing unique translocations that originate gene rearrangements. This category includes rhabdomyosarcoma (RMS), Ewing's sarcoma (ES) and synovial sarcoma (SS). Diverse studies have related development genes, such as; IGF2, IHH, PTCH1 and GLI1 and sarcomatogenesis.

OBJECTIVE

To characterize the RMS, ES and SS rearrangements, we quantify the expression of IGF2 IHH, PTCH1 and GLI1 genes and correlate molecular data with clinical parameters of patients.

DESIGN

We analyzed 29 RMS, 10 SS and 60 ES tumor samples by RT-PCR (polymerase chain reaction-reverse transcription) and qPCR (quantitative PCR).

RESULTS

Among the samples of ARMS, 50% had rearrangements of PAX3/7-FOXO1, 60% of ES samples were EWS-FLI1 positive and 90% of SS samples were positive for SS18-SSX1/2. In relation to the control reference samples (QPCR Human Reference Total RNA-Stratagene, Human Skeletal Muscle Total RNA-Ambion, Universal RNA Human Normal Tissues-Ambion), RMS samples showed a high IGF2 gene expression (p<0.0001). Moreover, ES samples showed a low IGF2 gene expression (p<0.0001) and high IHH (p<0.0001), PTCH1 (p=0.0173) and GLI1 (p=0.0113) gene expressions.

CONCLUSIONS

The molecular characterization of IGF and Hedgehog pathway in these pediatric sarcomas may collaborate to enable a better understanding of the biological behavior of these neoplasms.

Primary synovial sarcomas of the mediastinum: a systematic review and pooled analysis of the published literature

Background. The aim of this systematic review is to attempt to provide a descriptive analysis for cases of synovial sarcoma (SS) arising in the mediastinum and to analyze prognostic factors. Methods. We performed PubMed database search in July 2013. Twenty-two studies, which included 40 patients, form the basis of this review. Demographic and disease-related factors were analyzed for possible influence on survival. Findings were compared with extremity SS studies reported in literature. Results. Sixteen cases (40%) presented with locally advanced unresectable disease, 2 (5%) with metastatic disease, and 22 (55%) with localized resectable disease. Median tumor size was 11 cm (range: 5–20 cm). Thirty patients were assessable for survival and had a 5-year OS of 36%. Completeness of resection was the only factor associated with significant improvement in OS (5-year survival of 63% and 0% in favor of complete resection, P = 0.003). Conclusion. Mediastinal SS is associated with poor prognosis as more cases are diagnosed at an advanced stage and with larger tumor size compared to extremity SS. Complete surgical resection is the only identified factor associated with better prognosis and may result in survival outcomes that are comparable with those for localized SS of the extremity.

Diagnostic utility of SOX10 to distinguish malignant peripheral nerve sheath tumor from synovial sarcoma, including intraneural synovial sarcoma

Synovial sarcoma and malignant peripheral nerve sheath tumor pose a significant diagnostic challenge given similar histomorphology. The distinction is further complicated by similar immunophenotype and especially by occasional synovial sarcomas that present as intraneural tumors. Although the presence of a t(X;18) rearrangement or expression of TLE1 can help confirm the diagnosis of synovial sarcoma, negative results for these tests are not diagnostic of malignant peripheral nerve sheath tumor. The SOX10 transcription factor, a putative marker of neural crest differentiation, may have diagnostic utility in this differential, but immunohistochemical data are limited. The goal of the present study was to determine the diagnostic utility of SOX10 to discriminate between synovial sarcoma and malignant peripheral nerve sheath tumor. Forty-eight cases of malignant peripheral nerve sheath tumor, all from patients with documented neurofibromatosis, and 97 cases of genetically confirmed synovial sarcoma, including 4 intraneural synovial sarcomas, were immunohistochemically stained for SOX10. The stain was scored for intensity and fraction of cells staining. Thirty-two of 48 malignant peripheral nerve sheath tumors (67%) were SOX10-positive. The majority of malignant peripheral nerve sheath tumors showed ≥2+ staining, but staining did not correlate with grade. By contrast, only 7/97 (7%) synovial sarcomas were SOX10-positive. Only three synovial sarcomas showed ≥2+ staining but, importantly, two of these were intraneural synovial sarcoma. Therefore, SOX10 is a specific (93%), albeit not very sensitive (67%), diagnostic marker to support a diagnosis of malignant peripheral nerve sheath tumor over synovial sarcoma. Furthermore, the stain needs to be interpreted with caution in intraneural tumors in order to avoid a potential diagnostic pitfall. It remains to be determined whether SOX10-positive cells in intraneural synovial sarcoma represent entrapped Schwann cells, synovial sarcoma cells or both.

SS18-SSX fusion protein-induced Wnt/β-catenin signaling is a therapeutic target in synovial sarcoma

Synovial sarcoma is a high-grade soft tissue malignancy characterized by a specific reciprocal translocation t(X;18), which leads to the fusion of the SS18 (SYT) gene to one of three SSX genes (SSX1, SSX2 or SSX4). The resulting chimeric SS18-SSX protein is suggested to act as an oncogenic transcriptional regulator. Despite multimodal therapeutic approaches, metastatic disease is often lethal and the development of novel targeted therapeutic strategies is required. Several expression-profiling studies identified distinct gene expression signatures, implying a consistent role of Wnt/β-catenin signaling in synovial sarcoma tumorigenesis. Here we investigate the functional and therapeutic relevance of Wnt/β-catenin pathway activation in vitro and in vivo. Immunohistochemical analyses of nuclear β-catenin and Wnt downstream targets revealed activation of canonical Wnt signaling in a significant subset of 30 primary synovial sarcoma specimens. Functional aspects of Wnt signaling including dependence of Tcf/β-catenin complex activity on the SS18-SSX fusion proteins were analyzed. Efficient SS18-SSX-dependent activation of the Tcf/β-catenin transcriptional complex was confirmed by TOPflash reporter luciferase assays and immunoblotting. In five human synovial sarcoma cell lines, inhibition of the Tcf/β-catenin protein-protein interaction significantly blocked the canonical Wnt/β-catenin signaling cascade, accompanied by the effective downregulation of Wnt targets (AXIN2, CDC25A, c-MYC, DKK1, CyclinD1 and Survivin) and the specific suppression of cell viability associated with the induction of apoptosis. In SYO-1 synovial sarcoma xenografts, administration of small molecule Tcf/β-catenin complex inhibitors significantly reduced tumor growth, associated with diminished AXIN2 protein levels. In summary, SS18-SSX-induced Wnt/β-catenin signaling appears to be of crucial biological importance in synovial sarcoma tumorigenesis and progression, representing a potential molecular target for the development of novel therapeutic strategies.

Truncated SSX protein suppresses synovial sarcoma cell proliferation by inhibiting the localization of SS18-SSX fusion protein

Synovial sarcoma is a relatively rare high-grade soft tissue sarcoma that often develops in the limbs of young people and induces the lung and the lymph node metastasis resulting in poor prognosis. In patients with synovial sarcoma, specific chromosomal translocation of t(X; 18) (p11.2;q11.2) is observed, and SS18-SSX fusion protein expressed by this translocation is reported to be associated with pathogenesis. However, role of the fusion protein in the pathogenesis of synovial sarcoma has not yet been completely clarified. In this study, we focused on the localization patterns of SS18-SSX fusion protein. We constructed expression plasmids coding for the full length SS18-SSX, the truncated SS18 moiety (tSS18) and the truncated SSX moiety (tSSX) of SS18-SSX, tagged with fluorescent proteins. These plasmids were transfected in synovial sarcoma SYO-1 cells and we observed the expression of these proteins using a fluorescence microscope. The SS18-SSX fusion protein showed a characteristic speckle pattern in the nucleus. However, when SS18-SSX was co-expressed with tSSX, localization of SS18-SSX changed from speckle patterns to the diffused pattern similar to the localization pattern of tSSX and SSX. Furthermore, cell proliferation and colony formation of synovial sarcoma SYO-1 and YaFuSS cells were suppressed by exogenous tSSX expression. Our results suggest that the characteristic speckle localization pattern of SS18-SSX is strongly involved in the tumorigenesis through the SSX moiety of the SS18-SSX fusion protein. These findings could be applied to further understand the pathogenic mechanisms, and towards the development of molecular targeting approach for synovial sarcoma.

Synovial sarcoma presenting with huge mediastinal mass: a case report and review of literature

Background

Synovial sarcoma presenting in the mediastinum is exceedingly rare. Furthermore, data addressing optimal therapy is limited. Herein we present a case where an attempt to downsize the tumor to a resectable state with chemotherapy was employed.

Case presentation

A 32 year female presented with massive pericardial effusion and unresectable huge mediastinal mass. Computed axial tomography scan - guided biopsy with adjunctive immunostains and molecular studies confirmed a diagnosis of synovial sarcoma. Following three cycles of combination Ifosfamide and doxorubicin chemotherapy, no response was demonstrated. The patient refused further therapy and had progression of her disease 4 months following the last cycle.

Conclusion

Synovial sarcoma presenting with unresectable mediastinal mass carry a poor prognosis. Up to the best of our knowledge there are only four previous reports where primary chemotherapy was employed, unfortunately; none of these cases had subsequent complete surgical resection. Identification of the best treatment strategy for patients with unresectable disease is warranted. Our case can be of benefit to medical oncologists and thoracic surgeons who might be faced with this unique and exceedingly rare clinical scenario.

Recurrent and novel SS18-SSX fusion transcripts in synovial sarcoma: description of three new cases

Synovial sarcoma (SS) is an aggressive type of tumor, comprising approximately 10 % of soft tissue sarcomas. Over 90 % of SS cases are characterized by the t(X;18)(p11.2;q11.2) translocation, which results mainly in the formation of oncogenic SS18-SSX1 or SS18-SSX2 fusions. In a typical SS18-SSX fusion transcript, exon 10 of SS18 is fused to exon 6 of SSX1/2. However, several variant fusion transcripts have been already described. In the present study, we examined the fusion transcript type in a series of 40 primary untreated SS tumor specimens using reverse transcription polymerase chain reaction and fluorescence in situ hybridization assay. We detected SS18-SSX1 transcript in 22 (55 %) patients and SS18-SSX2 transcript in 17 (42.5 %) patients, while in one patient, none of SS18-SSX1/2 fusion transcripts were identified. Among the cases under study, two tumors carried novel SS18-SSX1 and SS18-SSX2 variant translocations that were allegedly created by an alternative splicing, and in additional case, an unusual translocation variant previously described by other group was found. Our data suggest that alternative splicing may play an important role in novel fusion transcript formation, and additionally we show that it may be a recurrent event in SS. Furthermore, we describe the first case of a complex rearrangement possibly linking SS to REPS2 gene.

Downstream and intermediate interactions of synovial sarcoma-associated fusion oncoproteins and their implication for targeted therapy

Synovial sarcoma (SS), an aggressive type of soft tissue tumor, occurs mostly in adolescents and young adults. The origin and molecular mechanism of the development of SS remain only partially known. Over 90% of SS cases are characterized by the t(X;18)(p11.2;q11.2) translocation, which results mainly in the formation of SS18-SSX1 or SS18-SSX2 fusion genes. In recent years, several reports describing direct and indirect interactions of SS18-SSX1/SSX2 oncoproteins have been published. These reports suggest that the fusion proteins particularly affect the cell growth, cell proliferation, TP53 pathway, and chromatin remodeling mechanisms, contributing to SS oncogenesis. Additional research efforts are required to fully explore the protein-protein interactions of SS18-SSX oncoproteins and the pathways that are regulated by these partnerships for the development of effective targeted therapy.

Synovial Sarcoma of the Brachial Plexus

BACKGROUND AND IMPORTANCE:

Synovial sarcoma (SS) is a malignant soft-tissue tumor that rarely involves brachial plexus. The authors report a case of brachial plexus SS and review the relevant literature.

CLINICAL PRESENTATION:

A 53-year-old woman presented with gradually enlarging right subclavicular mass over 5 years associated with sharp aching pain radiating down toward the radial 3 fingers. On examination, she had a corresponding firm mass in the supraclavicular region with a positive Tinel sign. There was no objective neurological deficit. She underwent partial excision of this mass without any further adjuvant radiation or chemotherapy. Pathology was consistent with SS.

CONCLUSION:

Lack of any recurrence in this case 6 years after incomplete excision with no adjuvant therapy suggests slow clinical course in some of these sarcomas.

[Rare primary chest wall sarcoma: the synovialosarcoma]

INTRODUCTION

Malignant primary tumours occurring in the thorax encompass a large group of tumours which may arise from the lung, mediastinal structures, the pleura or the chest wall.

OBSERVATION

We report the case of a 37 year old patient, who presented with left sided chest pain. On clinical examination a right sided chest wall mass was identified. Chest X Ray showed a left sided upper mediastinal opacity, associated with a left sided pleural opacity. Thoracic CT scan revealed a large mass arising from the chest wall and infiltrating the mediastinum associated with a second chest wall mass at the level of the 8(th) and 9(th) right ribs. The biopsy of the chest wall mass revealed it to be a parietal synovialosarcoma. The patient responded to chemotherapy based on ifosfamid and doxorubicin as well as mediastino-pulmonary radiotherapy. There was an improvement in the patient's clinical and radiological state but the patient died by pulmonary embolism after the 3(rd) cause of treatment.

CONCLUSION

Chest wall synovialosarcoma has a poor prognosis, however, its chemosensitivity means that treatment may initially be effective.

Targeting the p53 Pathway in Ewing Sarcoma

The p53 tumour suppressor plays a pivotal role in the prevention of oncogenic transformation. Cancers frequently evade the potent antitumour surveillance mechanisms of p53 through mutation of the TP53 gene, with approximately 50% of all human malignancies expressing dysfunctional, mutated p53 proteins. Interestingly, genetic lesions in the TP53 gene are only observed in 10% of Ewing Sarcomas, with the majority of these sarcomas expressing a functional wild-type p53. In addition, the p53 downstream signaling pathways and DNA-damage cell cycle checkpoints remain functionally intact in these sarcomas. This paper summarizes recent insights into the functional capabilities and regulation of p53 in Ewing Sarcoma, with a particular focus on the cross-talk between p53 and the EWS-FLI1 gene rearrangement frequently associated with this disease. The development of several activators of p53 is discussed, with recent evidence demonstrating the potential of small molecule p53 activators as a promising systemic therapeutic approach for the treatment of Ewing Sarcomas with wild-type p53.

New insights in sarcoma oncogenesis: a comprehensive analysis of a large series of 160 soft tissue sarcomas with complex genomics

Adult soft tissue sarcomas (STS) are rare tumours of mesenchymal lineage. Based on cytogenetic and comparative genomic hybridization (CGH) data, they can be divided into 'STS with simple genomics', displaying a characteristic genetic alteration, and 'STS with complex genomics' (SCG), where multiple genomic alterations occur. This latter group is mostly composed of leiomyosarcomas (LMS) and pleiomorphic undifferentiated tumours previously labelled as 'malignant fibrous histiocytomas' (MFH), corresponding in fact to myxofibrosarcomas (MFS), pleiomorphic liposarcomas/rhabdomyosarcomas (P-LPS, P-RMS), and undifferentiated pleiomorphic sarcomas (UPS). Their pathobiology is still not well understood, leading to challenges in diagnosis and therapeutic management. We report here a comprehensive study encompassing array-CGH and transcriptome analysis data of a large series of 160 SCG. Non-supervised clustering of transcriptome data led to the identification of five groups of tumours, one of them (group A) corresponding to well-differentiated LMS and the other four (B-E) to 'MFH' and poorly differentiated LMS. Welch analysis of transcriptome data in these groups allowed us to retrieve several genes of potential interest. Among them, RB1 alteration is a constant thread in SCG, often associated with RBL2 loss. PTEN tumour suppressor deletion would also stand out as a major recurrent event, especially in groups A, C, and D. The WNT canonical pathway could be potentially involved, as demonstrated by up-regulation of one of its inhibitors, DKK1, in groups D and E, whereas DKK1 is significantly down-regulated in groups A, B, and C. These data suggest a very complex interplay between pathways downstream of PTEN and the WNT canonical pathway, providing new hints about SCG pathobiology and their potential therapeutic targets.

Inhibition of proliferation and gene expression regulation by (-)-epigallocatechin-3-gallate in human synovial sarcoma cells

Synovial sarcoma is an aggressive soft-tissue malignancy with poor prognosis and lack of response to conventional cytotoxic chemotherapy. The regulatory mechanisms for the rapid proliferation of synovial sarcoma cells and the particular aggressiveness of this sarcoma remain poorly understood. In this study, we investigate the effect of epigallocatechin-3-gallate (EGCG) on growth and apoptosis of chondrosarcoma cells. The MTT assay and DAPI staining indicated that EGCG effectively inhibited cellular proliferation and induces apoptosis of the synovial sarcoma cells and induced apoptosis as confirmed by flow cytometry. Furthermore, Bcl-2 and Mcl-1 levels significantly decreased, Bax levels significantly increased, whereas expression levels of the proteins Bcl-XL were unchanged in response to EGCG treatment in SW982. In conclusion, our findings demonstrate that EGCG is effective for growth inhibition of synovial sarcoma cell lines in vitro and suggest that EGCG may be a new therapeutic option for patients with synovial sarcoma.

Cryptic SYT/SXX1 fusion gene in high-grade biphasic synovial sarcoma with unique complex rearrangement and extensive BCL2 overexpression

Synovial sarcomas are high-grade malignant mesenchymal tumors that account for 10% of all soft-tissue sarcomas. Almost 95% of these tumors are characterized by a nonrandom chromosomal abnormality, t(X;18)(p11.2;q11.2), that is observed in both biphasic and monophasic variants. In this article, we present the case of a 57-year-old woman diagnosed with high-grade biphasic synovial sarcoma in which conventional cytogenetic analysis revealed the constant presence of a unique t(18;22)(q12;q13), in addition to trisomy 8. The rearrangement was confirmed by fluorescence in situ hybridization. The use of the whole chromosome painting probes WCPX did not detect any rearrangements involving chromosome X, although reverse-transcriptase polymerase chain reaction (PCR) analysis demonstrated the conspicuous presence of a SYT/SXX1 fusion gene. Spectral karyotyping (SKY) was also performed and revealed an insertion of material from chromosome 18 into one of the X chromosomes at position Xp11.2. Thus, the karyotype was subsequently interpreted as 47,X,der(X)ins(X;18)(p11.2;q11.2q11.2),der(18)del(18)(q11.2q11.2)t(18;22)(q12;q13),der(22)t(18;22). Real-time PCR analysis of BCL2 expression in the tumor sample showed a 433-fold increase. This rare finding exemplifies that thorough molecular-cytogenetic analyses are required to elucidate complex and/or cryptic tumor-specific translocations.

The benefits of molecular pathology in the diagnosis of musculoskeletal disease : part I of a two-part review: soft tissue tumors

Bone and soft tissue metabolic and neoplastic diseases are increasingly characterized by their molecular signatures. This has resulted from increased knowledge of the human genome, which has contributed to the unraveling of molecular pathways in health and disease. Exploitation of this information has allowed it to be used for practical diagnostic purposes. The aim of the first part of this two-part review is to provide an up-to-date review of molecular genetic investigations that are available and routinely used by specialist musculoskeletal histopathologists in the diagnosis of neoplastic disease. Herein we focus on the benefits of employing well characterized somatic mutations in soft tissue lesions that are commonly employed in diagnostic pathology today. The second part highlights the known somatic and germline mutations implicated in osteoclast-rich lesions of bone, and the genetic changes that disturb phosphate metabolism and result in a variety of musculoskeletal phenotypes. Finally, a brief practical guide of how to use and provide a molecular pathology service is given.

[Assessment of prognostic factors of thoracic synovial sarcoma]

INTRODUCTION

Synovial sarcoma is an uncommon tumour and thoracic involvement is rare and of varying location. Clinical characteristics are dominated by pain, with a slow progression over years. Pathological and immuno-histochemical characteristics are helpful in the diagnosis but a specific translocation between chromosomes X and 18 is crucial for confirmation. Extensive surgical resection is required for cure, combined with adjuvant radiotherapy in the presence of adverse prognostic factors.

CASE REPORT

We report a case of synovial sarcoma of the chest wall, responsible for chronic local pain for several years, presenting as an acute pleuropneumonitis in a 21-year-old patient. In view of the large size of the tumour, associated with a high proliferation index (Ki-67), a surgical resection was performed, together with local adjuvant radiotherapy.

CONCLUSION

This case report reviews synovial sarcoma and underlines the difficulties and requirements of both diagnostic strategy and therapeutic management. Among them, an initial systematic review of prognostic factors (tumour size, mitotic activity, proliferation index, SYT-SSX type fusion, histological grade) is crucial to determine the therapeutic options.

Small round cell sarcomas

Small round cell sarcomas are the most aggressive of the tumors morphologically and clinically encountered in children and adults, and in some ways the most leukemia- or lymphoma-like of sarcomas. Small round cell sarcomas often are associated with chromosomal translocations, like hematologic malignancies, and are usually more sensitive to chemotherapy than other sarcoma subtypes. They have a high risk of mortality, but chemotherapy (in addition to surgery and often radiation therapy) provides a good cure rate, although treatment is often long and intensive. The biology of these tumors is very telling in terms of some of the mechanisms of cancer cell survival and proliferation. Although there is some overlap of the discussion below with the section on translocation associated sarcomas, we have highlighted some of the key issues with these sarcomas below, with some ideas that may bear fruit both in terms of the management of these, other sarcomas, and other cancers alike.

Liposarcomatous differentiation in malignant peripheral nerve sheath tumor: a case report

A 63-year-old man was admitted at the emergency department in an acute confusional state, and a computerized tomography scan (CT) revealed hydrocephalus. Despite the rapid introduction of a ventriculo-peritoneal shunt, the patient died soon thereafter. At the post-mortem examination, a large solid mass was found to be firmly attached to a nerve root at the L1-L2 level. Microscopically, the tumor showed the classical features of a malignant peripheral nerve sheath tumor (MPNST) with rhabdomyoblastic differentiation. In addition, there were randomly distributed lobules of well-differentiated adipose tissue with unequivocal atypical nuclei. The diagnosis of MPNST with rhabdomyoblastic and lipoblastic differentiation was made. We are not aware of previously reported lipoblastic differentiation in MPNST. Herein, we present details of the case.

Activation of the non-canonical Dvl-Rac1-JNK pathway by Frizzled homologue 10 in human synovial sarcoma

We previously reported that Frizzled homologue 10 (FZD10), a member of the Wnt signal receptor family, was highly and specifically upregulated in synovial sarcoma and played critical roles in its cell survival and growth. We here report a possible molecular mechanism of the FZD10 signaling in synovial sarcoma cells. We found a significant enhancement of phosphorylation of the Dishevelled (Dvl)2/Dvl3 complex as well as activation of the Rac1-JNK cascade in synovial sarcoma cells in which FZD10 was overexpressed. Activation of the FZD10-Dvls-Rac1 pathway induced lamellipodia formation and enhanced anchorage-independent cell growth cells. FZD10 overexpression also caused the destruction of the actin cytoskeleton structure, probably through the downregulation of the RhoA activity. Our results have strongly implied that FZD10 transactivation causes the activation of the non-canonical Dvl-Rac1-JNK pathway and plays critical roles in the development/progression of synovial sarcomas.

Primary synovial sarcoma of the kidney with rhabdoid features

Synovial sarcoma is a soft tissue sarcoma with clearly defined histologic, immunophenotypic, and molecular features. It occurs predominantly in the extremities of young adults but has been reported in many other anatomic sites. Histologically, it is classified as biphasic, monophasic, and poorly differentiated. The latter category, which includes tumors with a rhabdoid morphology, has been associated with a more aggressive behavior. Generally, the biphasic variant does not pose any diagnostic problem because of its typical histologic appearance; in contrast, the monophasic and poorly differentiated variants may represent a diagnostic challenge because their microscopic features can be confused with those of other spindle cell tumors with rhabdoid features. The application of molecular techniques, such as reverse transcriptase polymerase chain reaction to detect the fusion transcript associated with the characteristic t(X;18) translocation of synovial sarcoma, has enabled the confirmation of this diagnosis, even in cases of unusual localization, such as the one we present here.

Molecular target therapy for synovial sarcoma

Although the specific chromosomal translocation and fusion gene SYT-SSX in synovial sarcoma (SS) has been identified, the molecular mechanism of its tumorigenesis is largely unknown. Recent gene-expression profiles of soft-tissue tumors using cDNA microarray demonstrated that SS has the distinct gene-expression pattern from other sarcomas and has a similar pattern to that of malignant peripheral nerve sheath tumors, indicating that the origin of SS is likely to be the neural crest cells. Through this analysis, several genes were found to be specifically upregulated in SS and considered to play an important role in the proliferation of SS cells. Among them, Frizzled homolog 10 was identified as a good candidate molecule for the development of novel therapies to treat SS patients.

Primary monophasic mediastinal, cardiac and pericardial synovial sarcoma: a young man in distress

A 19-year-old male was admitted because of exertional dyspnoea. The imaging studies revealed epicardial, pericardial and mediastinal masses. The tumours could not be resected through a minor thoracotomy, only biopsies could be taken. Analyses led to the final diagnosis of a monophasic synovial sarcoma. The patient preferred a conservative and palliative approach. Three months later he died at home. Autopsy demonstrated dramatic extension of the tumour masses. We conclude this report with a discussion on primary cardiac tumours. (Neth Heart J 2007;15:226-8.).

Detection of SS18-SSX fusion transcripts in formalin-fixed paraffin-embedded neoplasms: analysis of conventional RT-PCR, qRT-PCR and dual color FISH as diagnostic tools for synovial sarcoma

Synovial Sarcoma consistently harbors t(X;18) resulting in SS18-SSX1, SS18-SSX2 and rarely SS18-SSX4 fusion transcripts. Of 328 cases included in our study, synovial sarcoma was either the primary diagnosis or was very high in the differential diagnosis in 134 cases: of these, amplifiable cDNA was obtained from 131. SS18-SSX fusion products were found in 126 (96%) cases (74 SS18-SSX1, 52 SS18-SSX2), using quantitative and 120 by conventional reverse transcriptase-polymerase chain reaction (RT-PCR). One hundred and one cases in a tissue microarray, analyzed by fluorescence in situ hybridization (FISH), revealed that 87 (86%) showed SS18 rearrangement: four RT-PCR positive cases, reported as negative for FISH, showed loss of one spectrum green signal, and 15 cases had multiple copies of the SS18 gene: both findings are potentially problematic when interpreting results. One of three cases, not analyzed by RT-PCR reaction owing to poor quality RNA, was positive by FISH. SS18-SSX1 was present in 56 monophasic and 18 biphasic synovial sarcoma: SS18-SSX2 was detected in 41 monophasic and 11 biphasic synovial sarcoma. Poorly differentiated areas were identified in 44 cases (31%). There was no statistically significant association between biphasic, monophasic and fusion type. Five cases were negative for SS18 rearrangement by all methods, three of which were pleural-sited neoplasms. Following clinical input, a diagnosis of mesothelioma was favored in one case, a sarcoma, not otherwise specified in another and a solitary fibrous tumor in the third case. The possibility of a malignant peripheral nerve sheath tumor could not be excluded in the other two cases. We concluded that the employment of a combination of molecular approaches is a powerful aid to diagnosing synovial sarcoma giving at least 96% sensitivity and 100% specificity but results must be interpreted in the light of other modalities such as clinical findings and immunohistochemical data.

Primary Synovial Sarcoma in Fallopian Tube

Synovial sarcoma, a malignant mesenchymal neoplasm, occurs mostly near the joints of the extremities and occasionally outside the joint such as lung. We report a case of soft tissue sarcoma arising in the fallopian tube origin that showed characteristic pathological appearance of biphasic synovial sarcoma. Molecular analysis detected a fusion gene transcript of synovial sarcoma translocation (SYT) gene from chromosome 18 and synovial sarcoma X chromosome breakpoint 1 (SSX1) gene, which is believed to pathognomonic for synovial sarcoma of joint origin. Recurrent abdominal tumor, observed at 12 month after the initial surgery and following chemotherapy using doxorubicin, cisplatin and ifosfamide, partially responded to chemotherapy using paclitaxel and carboplatin and, then, optimal surgery was performed. This is the first report of a synovial sarcoma arising in the fallopian tube.

Identification of SYT-SSX transcripts from synovial sarcomas using RT-multiplex PCR and capillary electrophoresis

Synovial sarcomas are highly malignant tumors of soft tissue which are characterized by the t(X;18) resulting in SYT-SSX fusion transcript production. Diagnosis of these tumors based on histology can be challenging, particularly when minimal biopsy specimens are presented to the pathologist. Demonstration by molecular methods of SYT-SSX transcripts is a useful adjunct for diagnosis in these situations. We have developed an assay, which combines one-step RT-multiplex PCR with capillary electrophoresis to detect and genotype the SYT-SSX transcripts from synovial sarcomas. Small amplicons from chimeric transcripts as well as GAPD transcripts are differentially labeled with fluorophores, allowing detection and size discrimination by capillary electrophoresis. In a study of 32 formalin-fixed soft tissue tumor specimens, the assay detected chimeric transcripts from 17/22 (77%) synovial sarcomas. All five assay negative specimens yielded no intact RNA as evidenced by lack of a GAPD amplicon. Chimeric transcripts were not detected in 9/9 malignant peripheral nerve sheath tumors or 1/1 epithelioid sarcoma. Representative amplicons were sequenced and confirmed the genotype results obtained by capillary electrophoresis. One-step RT-multiplex PCR combined with capillary electrophoresis is a rapid and accurate method for the detection and genotypic classification of SYT-SSX transcripts from fixed tissue specimens.

Hemangiopericytoma-like synovial sarcoma of the lumbar spine

✓The purpose of this report is to demonstrate that synovial sarcoma should be included in the differential diagnosis of tumors originating from the lumbar spine, especially if they show hemangiopericytoma-like pathological characteristics. A synovial sarcoma is a mesenchymal spindle cell tumor that displays variable epithelial differentiation including glandular formation. It is unrelated to a synovium. More than 80% of these lesions arise in the deep soft tissue of the extremities. The tumor frequently arises adjacent to joints or tendon sheaths. The authors describe a young woman with a hemangiopericytoma-like tumor of the lumbar spine. During repeated operation, this lesion was shown to be a synovial sarcoma, which had invaded the dura mater. The tumor metastasized to the mediastinum and the intradural cervical spine and, finally, to the brain and the lungs. To the authors’ knowledge, this is the first reported case of a synovial sarcoma originating from the lumbar spine.

A case of pulmonary synovial sarcoma diagnosed with detection of chimera gene

Pulmonary synovial sarcoma is a rare disease, and reports detailing clinicians' radiological findings are few. We report a case of a primary pulmonary synovial sarcoma in a 68-year-old woman. Chest CT revealed a well-defined and homogeneous oval mass measuring 3x2.5 cm in the left lower lobe in contact with the visceral pleura. No pleural effusion was evident. No calcification or fat component was detected. The tumor showed homogeneous hypointensity on both T1- and T2-weighted MR imaging. In this case, a lung metastasis could be excluded with fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET), and the final diagnosis was histopathologically confirmed by the chimeric gene detection.

A molecular map of mesenchymal tumors

A comprehensive study of the gene expression profile of 96 mesenchymal tumors identifies molecular fingerprints for most tumors in this group.

Background

Bone and soft tissue tumors represent a diverse group of neoplasms thought to derive from cells of the mesenchyme or neural crest. Histological diagnosis is challenging due to the poor or heterogenous differentiation of many tumors, resulting in uncertainty over prognosis and appropriate therapy.

Results

We have undertaken a broad and comprehensive study of the gene expression profile of 96 tumors with representatives of all mesenchymal tissues, including several problem diagnostic groups. Using machine learning methods adapted to this problem we identify molecular fingerprints for most tumors, which are pathognomonic (decisive) and biologically revealing.

Conclusion

We demonstrate the utility of gene expression profiles and machine learning for a complex clinical problem, and identify putative origins for certain mesenchymal tumors.

Significant growth suppression of synovial sarcomas by the histone deacetylase inhibitor FK228 in vitro and in vivo

About 97% of synovial sarcomas harbor the SYT-SSX fusion gene by chromosomal translocation. We found that the histone deacetylase (HDAC) inhibitor FK228 significantly suppressed the growth of synovial sarcoma cells as compared with that of osteosarcoma. The 50% growth inhibition IC50 value we obtained for FK228 was 0.02-0.2 nM, and it indicates that its suppression effect on synovial sarcoma cells is the highest of any of the HDAC inhibitors yet reported. It was not likely that the growth suppression of FK228 depends on the doubling time of these cells. Introduction of SYT-SSX cDNA into HEK293 cells enhanced the sensitivity of the cells for FK228. Immunostaining of the FK228-treated cells using an anti-acetyl-histone H3 antibody showed that FK228 inhibits deacetylation of histone. In a mice assay, the growth of synovial sarcoma cells was markedly inhibited by FK228 treatment, and the invasion of tumors into surrounding tissues was suppressed. These results suggest that FK228 may be useful in developing therapeutic strategies to treat synovial sarcoma.

Synovial sarcoma of the nasal septum

No case of synovial sarcoma of the nasal septum has so far been reported. We present a patient with synovial sarcoma of the nasal septum and review the related literature. The patient underwent local excision without adjuvant therapy. There was no local recurrence or distant metastasis in the 18-month follow-up period.

Unusual cytogenetic findings in a synovial sarcoma arising in the paranasal sinuses

A fresh specimen from an intracranial tumor, which was histopatologically classified as a synovial sarcoma, was investigated cytogenetically. The direct method failed to give any information due to a lack of mitotic cells after treatment with 70% acetic acid, whereas 6-day cultures showed a 45,XY,del(6q),-10 karyotype. The histologic evaluation was consistent with a synovial sarcoma, which is well characterized from a cytogenetic perspective and involves a t(X;18)(p11;q11) in more than 95% of cases. Reverse-transcription polymerase chain reaction analysis did not show the presence of the SYT-SSX chimeric gene.