Primary pleural synovial sarcoma. A case report and review of the literature

Pleural malignant mesothelioma versus pleuropulmonary synovial sarcoma: a clinicopathological study of 22 cases with molecular analysis and survival data

The aim of this study was to carry out a comparative analysis by transducin-like enhancer of split 1 (TLE1) immunohistochemistry and molecular analysis of SYT-SSX, for 16 pleural predominantly sarcomatoid mesotheliomas and six cases of pleuropulmonary synovial sarcoma (five pleural in distribution only, with one case of a predominantly subpleural upper lobe synovial sarcoma), all of which were solely or predominantly monophasic. Our comparison included survival and some clinical data. We consider that the following points emerged from this study.

Primary monophasic synovial sarcoma of the pleura: Neoadjuvant chemotherapy followed by complete resection

We describe a rare case of primary pleural synovial sarcoma in a 27-year-old man with a 4-month history of dry cough and left-sided chest pain. A CT scan showed a large cystic mass in the left pleural cavity. The patient underwent two video-assisted thoracoscopic biopsies and the diagnosis of synovial sarcoma of the pleura was established. After neoadjuvant chemotherapy, which resulted in a partial response, the tumor was completely resected with extrapleural pneumonectomy. Pathological findings showed less than 5% of viable cancer and free surgical margins. The patient is clinically well 24 months after surgery, with no evidence of recurrent disease.

A giant pleural poorly differentiated synovial sarcoma (PDSS) in a 64-year-old woman

The article presents the rare case of a 64-year-old woman, who was admitted to our thoracic surgery department with a giant tumor in a right hemithorax measuring 88 mm × 137 mm × 188 mm, revealed by a thoracic CT scan. An anterolateral thoracotomy with a radical tumor resection was performed. The final pathological diagnosis of the poorly differentiated synovial sarcoma (PDSS) was made. The adjuvant radiotherapy of 60 Gy in 30 fractions was applied postoperatively. One year after operation patient remains in good health. The literature review on pleural synovial sarcoma has been shortly presented.

Extensive Surgical Treatment of Primary Pulmonary Synovial Sarcoma After Recurrent Pneumothorax

A 26-year-old woman with a history of right-sided recurrent pneumothorax and resection of pulmonary bullae, pleural abrasion, and talc pleurodesis underwent right-sided extensive pleural pneumonectomy for a monophasic primary pleural-pulmonary synovial sarcoma (PPSS). The pathologic diagnosis was predominantly fusiform PPSS with R0 resection. Sixteen months after the operation, she is alive, without signs of new lesions. The extensive tumor resection can achieve a good result for controlling local disease.

Primary Pleural Synovial Sarcoma Treated with Pazopanib

A 42-year-old woman presented with chest pain and breathlessness with a nodule measuring 2×2 cm in size at the base of the right lung. A bronchoscopic examination did not reveal any malignancy. However, the patient developed difficulty in breathing, enlargement of the nodule, and right pleural effusion 14 days later. A video-assisted thoracic surgical biopsy specimen revealed the presence of pleural synovial sarcoma. The patient was treated with doxorubicin-ifosfamide combination chemotherapy because of metastasis to the pelvis. However, after a transient partial clinical response, there was a relapse of refractory disease. Although treated with pazopanib as second-line chemotherapy, the patient died eight months after the initial presentation.

Rare pleural tumors

Primary pleural tumors other than mesothelioma account for fewer than 1% of all lung cancers, and consequently they pose diagnostic and management challenges. Their treatment must be targeted toward the specific tumor type and is often quite different from the treatment for mesothelioma or metastases. Despite the best efforts at diagnosing and treating these tumors, the prognosis associated with some of the benign and many of the malignant variants of these tumors remains poor. In this review, we describe the radiologic and pathologic features of the less common primary pleural tumors and propose a diagnostic approach to their evaluation.

Pathohistological diagnosis and differential diagnosis

Malignant mesothelioma is a rare aggressive tumour arising from mesothelial cells of the pleural and peritoneal cavity including pericardium and tunica vaginalis testis. Malignant mesothelioma occurs predominantly in men (>90%). Asbestos exposure is the best known and evaluated risk factor with a long latency period between exposure and onset of malignant mesothelioma ranging from 15 to 60 years. Exposure to erionite leads to higher incidences of mesothelioma and play an important role in environmental exposure (Turkey). Other possible risk factors are radiation, recurrent pleuritis/peritonitis and simian virus 40 (SV 40).Malignant pleural mesothelioma is most common, whereas malignant peritoneal mesothelioma accounts only for 6-10%. Infrequent sites of origin are the pericardium and tunica vaginalis in 1-2%.Malignant mesothelioma shows either diffuse growth pattern or occurs as a localised tumour mass. Diffuse type represents an aggressive tumour with poor prognosis and is incurable in most cases.According to the WHO classification, three histological subtypes are distinguished: epithelioid, sarcomatoid and biphasic malignant mesothelioma.Rare variants are desmoplastic type, a subtype of sarcomatoid mesothelioma, undifferentiated type and deciduoid type. Epithelioid type is the most frequent one, but biphasic malignant mesothelioma occurs in 30%. Pure sarcomatoid or biphasic type is seen less frequently in malignant peritoneal mesothelioma than in its pleural counterpart.Well-differentiated papillary mesothelioma is a generally non-invasive mesothelioma with low malignant potential that arises mostly in females in the peritoneal cavity. Histological type is an important prognostic marker. Longest survival is seen in patients with epithelioid malignant mesothelioma. Sarcomatoid subtype has the worst prognosis.Malignant mesothelioma shows macroscopical and microscopical similarities to benign lesions and other malignancies. Therefore, reactive mesothelial proliferations on the one hand and secondary tumours resembling mesothelial cells as well as benign or rare mesothelial tumours on the other hand have to be distinguished. Additional immunohistochemistry is essential in histopathological assessment using a marker panel of antibodies.

Giant synovial cell sarcoma of the thorax in a 46-year-old man: a case report

Background

Although synovial cell sarcoma is a common tumor of the extremities, its occurrence in the thorax has been less frequently documented.

Case presentation

A 46-year-old Pakistani man presented with a 2 month history of progressively increasing cough and left lower chest pain. Initial evaluation was done using a chest x-ray; the patient was found to have a large mass involving the lower portion of the left chest. A computed tomography scan was performed next which showed a large mass involving the left chest wall with invasion into the pericardium and left hemidiaphragm. En bloc surgical resection of the tumor was undertaken. Final pathology showed synovial cell sarcoma of the thorax. At one-year follow-up, the patient has shown no recurrence of the disease.

Conclusion

We have described a rare case of a large synovial cell sarcoma of the thorax. Surgical resection appears an appropriate modus operandi for managing giant synovial cell sarcomas of the thorax. However, there is a need to clearly define post-operative strategies for cases with extensive involvement of surrounding structures.

Primary pleural neoplasia: entities other than diffuse malignant mesothelioma

CONTEXT

Overwhelmingly, the most common neoplasm involving the pleura is metastatic carcinoma. In contrast, diffuse malignant mesothelioma occurs relatively rarely; however, it is nonetheless the most common neoplasm primary to the pleura. Metastatic carcinoma and diffuse malignant mesothelioma each have their own prognostic and therapeutic characteristics. Other primary pleural neoplasms occur uncommonly or rarely, with their own prognostic and therapeutic characteristics.

OBJECTIVE

To review primary pleural neoplasms other than diffuse malignant mesothelioma, to better ensure correct diagnosis and optimal assessment of prognosis and treatment.

DATA SOURCES

Literature review and primary material from the authors' institutions.

CONCLUSIONS

A nonexhaustive group of uncommon to rare benign and malignant primary pleural neoplasms--other than diffuse malignant mesothelioma--are presented, of which one must be aware in order to maintain an appropriate index of suspicion to include them in the differential diagnosis of a pleural tumor.

Primary pleural synovial sarcoma presenting as a multiloculated cyst in an adolescent

Primary pleural synovial sarcoma (PPSS) is a rare pleural malignancy with a grave prognosis. Most cases present as a well-circumscribed mass with foci of haemorrhage and necrosis. We present an unusual case in a Nepalese boy that presented as a multiloculated cyst mimicking hydatid disease. The diagnosis was confirmed by histology and cytogenetic analysis.

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.

D2-40 and calretinin - a tissue microarray analysis of 341 malignant mesotheliomas with emphasis on sarcomatoid differentiation

Anti-calretinin antibodies are useful to differentiate adenocarcinomas from malignant mesotheliomas of the lung. Therefore, calretinin expression is rarely reported for sarcomatoid mesotheliomas. Anti-podoplanin antibodies (eg D2-40) react with lymphatic endothelia, Kaposi's sarcoma, lymphangioma and mesotheliomas. For the interpretation of spindle cell lesions of the pleura, knowledge of calretinin and D2-40 expression frequencies in sarcomatoid mesothelioma is desirable. To systematically investigate the sensitivity of calretinin and D2-40 antibodies in epithelioid and sarcomatoid areas of malignant mesotheliomas, a tissue microarray with 341 malignant mesotheliomas, including 112 epithelioid, 46 sarcomatoid and 183 biphasic tumors was constructed. Epithelioid and sarcomatoid differentiated tumor areas were clearly separated within the tissue microarray. Expression of calretinin and D2-40 was separately studied in epithelioid and sarcomatoid areas by immunohistochemistry. Calretinin expression was found in 91% of epithelioid and 57% of sarcomatoid tumor areas. D2-40 immunostaining was present in 66% of the epithelioid and 30% of the sarcomatoid tumor areas. A combination of calretinin and D2-40 increased the sensitivity in epithelioid tumor areas to 0.96 and in sarcomatoid tumor areas to 0.66. These data indicate that a combination of calretinin and D2-40 will improve diagnostic accuracy for spindle cell lesions of the pleura, whereas almost all epithelioid mesotheliomas are identified by calretinin alone.

Synovial sarcoma with radiological appearances of primitive neuroectodermal tumour/Ewing sarcoma: differentiation by molecular genetic studies

Synovial sarcoma (SS) arises in soft tissues but may invade adjacent bone. We describe a case of SS presenting as aggressive lysis of the proximal ulna, the imaging of which suggested a primary bone lesion. Needle biopsy showed a "small round blue cell tumour", and a primitive neuroectodermal tumour (PNET)/Ewing sarcoma was suggested on the basis of the imaging appearances. The definitive diagnosis of synovial sarcoma was made following molecular genetic studies, which demonstrated a fusion product incorporating the genes SYT and SSX1. The importance of correct diagnosis to guide appropriate management, and, therefore, the necessity for molecular genetic studies, is discussed.

Radiofrequency thermal ablation of primary pleural synovial sarcoma

Percutaneous radiofrequency (RF) thermal ablation has received attention as an effective minimally invasive approach for the treatment of a variety of neoplasms. However, the therapeutic efficacy of RF thermal ablation on primary pleural synovial sarcoma has not yet been reported. A 76-year-old man with a primary pleural synovial sarcoma who was medically inoperable received RF thermal ablation to achieve local control. Therefore, an RF electrode was inserted into the lesion and connected to an RF generator. In this report, a case of successful treatment of a primary pleural synovial sarcoma using RF ablation without complication is presented.

Identification of a ring chromosome with spectral karyotyping in a pleural synovial sarcoma

The origin of a ring chromosome in a monophasic synovial sarcoma of the diaphragmatic pleura of an 18-year-old man was investigated using spectral karyotyping (SKY) and fluorescence in situ hybridization (FISH). Conventional cytogenetic analysis revealed the following clonal karyotypic abnormalities: 47,Y,t(X;18)(p11.2;q11.2),t(11;19)(q12;q13.4),+12,-13,+r[6]. The SYT-SSX1 fusion transcript was detected with reverse transcriptase-polymerase chain reaction analysis. SKY analysis suggested that the ring chromosome was composed of material from chromosome 8. Subsequent FISH analysis with a whole-chromosome 8 paint probe confirmed the SKY results. This study demonstrates the usefulness of SKY as an adjunct for determining the chromosomal composition of ring chromosomes.

Scintigraphic findings in synovial sarcoma with structural correlation

Synovial sarcoma is a relatively rare malignant soft tissue tumour. It is highly aggressive, tends to occur in young adults and has a poor prognosis. The scintigraphic findings in 10 patients with histopathologically proven synovial sarcoma were reviewed. Most of the lesions occurred in the extremities and intense uptake of thallium was observed on 30-min and 4-h imaging in almost all cases. Thallium has an important role in the detection of possible metastatic disease and in monitoring response to therapy. The scintigraphic features of synovial sarcoma are presented and correlated with the radiographic findings.

Pathology of mesothelioma

In this article, progress in distinguishing mesothelioma from mesothelial hyperplasia and fibrosing pleuritis was discussed. Advances in the immunohistochemical characterization of mesothelioma, in the recognition of entities that mimic mesothelioma, and in their distinction from mesothelioma were reviewed. Cytogenetic and molecular genetic contributions to the diagnosis of pleural synovial sarcoma were briefly summarized. The diagnosis of epithelial type mesothelioma can be established in most cases. Several mesotheliomas, however, especially rare subtypes, and sarcomatoid, desmoplastic, and poorly differentiated mesotheliomas continue to present diagnostic challenges.

Mixed tumors of the vagina: an immunohistochemical study of 13 cases with emphasis on the cell of origin and potential aid in differential diagnosis

Mixed tumors of the vagina (MTsV) are rare benign neoplasms characterized by an admixture of well-differentiated epithelial cells and stromal-type cells in various proportions. In contrast to mixed tumors in other anatomic sites, the histogenesis of the vaginal tumors is unclear. We studied the immunohistochemical profile of 13 examples to explore their histogenesis and determine whether their immunohistochemical profile might be useful in the differential diagnosis. The panel of antibodies used and the number of cases studied were: AE1/3 (12), cytokeratin 7 (CK7) (13), cytokeratin 20 (CK20) (13), epithelial membrane antigen (EMA) (13), muscle actin (MA) (12), desmin (11), h-Caldesmon (13), CD10 (13), CD34 (11), CD99 (8), and S-100 (7). Eight out of 12 tumors were positive for AE1/3, 7/13 for CK7, 2/13 for CK20, and 6/13 for EMA. MA was positive in 11/12 mixed tumors, desmin in 10/11 tumors and h-Caldesmon in 5/13. All tumors were extensively positive for CD10; CD34 was positive in 7/11; and none out of eight tumors showed membranous CD99 staining. Focal S-100 immunoreactivity was seen in 1/7 tumors. These results show that MTsV coexpress epithelial and mesenchymal markers. The expression of muscle actin (usually extensive), and focal desmin and h-Caldesmon positivity suggests the presence of a smooth muscle or myoepithelial component; however, the S-100 negativity and diffuse CD10 expression argue against it. Positivity for muscle markers does not help distinguish MTsV from smooth muscle or skeletal muscle tumors. The frequent expression of CD10 negates its use in the differential diagnosis with endometrial stromal tumors, and the CD10 and CD34 expression suggests that mixed tumors may arise from a primitive pluripotential cell. MTsV are positive for h-Caldesmon and CD10, two markers that have been used in gynecologic pathology primarily to aid in establishing the smooth muscle or endometrial stromal phenotype of a neoplasm.