Primary Pulmonary Synovial Sarcoma in a Tertiary Referral Center: Clinical Characteristics, CT, and 18F-FDG PET Findings, With Pathologic Correlations

A giant synovial sarcoma of the left lung

Primary pulmonary synovial sarcoma is an extremely rare and aggressive neoplasm that primarily affects young people and has a poor prognosis. Establishing this diagnosis requires the exclusion of a wide number of other neoplasms with multimodal clinical, imaging, histological, immunohistochemical, and cytogenetic assessment. We present a case of synovial sarcoma of the left lung in a 44-year-old man, diagnosed immunohistochemically after left lower lobectomy with atypical resection of the 5th segment. Imaging, diagnostic workup, histological and immunohistochemical characteristics, surgical treatment, and prognosis are discussed.

Primary pulmonary synovial sarcoma with delayed diagnosis in a 69-year-old man: A case report

RATIONALE

Primary pulmonary synovial sarcoma is a rare malignant pulmonary tumor accompanied by calcifications in approximately 15% of cases. These calcifications usually have a fine, stippled appearance; coarse shapes have seldom been reported. Moreover, the presence of coarse calcifications often suggests benign tumors, which vastly differ in treatment. We present a rare case of primary pulmonary sarcoma with coarse intratumoral calcifications, the diagnosis of which was delayed because of its radiologic appearance.

PATIENT CONCERNS

A computed tomography (CT) scan of a 69-year-old man with right upper quadrant (RUQ) pain revealed an incidental mass at the base of the right lower lobe, the margin of which was not well described with respect to the liver, and intratumoral coarse calcification was noted. Initially, the lesion was believed to be hepatic, and magnetic resonance imaging (MRI) was performed. Based on its imaging features, the mass was thought to be a pulmonary lesion, and a preliminary diagnosis of a benign lesion, such as a hamartoma or granuloma, was made. Four months after the initial CT scan, the patient's RUQ pain had aggravated; however, no change in the mass was observed on follow-up CT.

DIAGNOSIS

The final diagnosis was primary pulmonary sarcoma, proven by surgical biopsy.

INTERVENTIONS

Wedge resection of the right lower lobe was performed, and the patient received adjuvant chemotherapy.

OUTCOMES

The patient's RUQ pain improved, and no recurrence or metastasis has been reported to date.

LESSONS

This case describes a rare presentation of a primary pulmonary synovial sarcoma with coarse intratumoral calcifications and the MRI features of the lesion. Intratumoral coarse calcifications often suggest benign lesions, such as hamartomas or post-inflammatory granulomas; however, as malignant lesions cannot be completely excluded, other radiologic and clinical features should be considered carefully. Focal areas of enhancement and eccentric calcification distribution might suggest malignant lesions such as primary pulmonary synovial sarcoma. Furthermore, despite not being used routinely, MRI scans might be helpful because advanced MRI techniques, such as diffusion-weighted imaging, can help distinguish malignant lesions from benign lesions. If the clinical course of a patient suggests malignancy, a more aggressive biopsy strategy should be considered.

Solitary primary pulmonary synovial sarcoma: A case report

BACKGROUND

Synovial sarcoma (SS) is an uncommon and highly malignant soft tissue sarcoma in the clinic, with primary pulmonary SS (PPSS) being extremely rare. Here, we describe the clinical characteristics, diagnosis, and treatment of a solitary PPSS case confirmed via surgical resection and fluorescence in situ hybridization (FISH).

CASE SUMMARY

A 33-year-old man was admitted because of intermittent coughing and hemoptysis for one month, with lung shadows observed for two years. Whole-body positron emission tomography-computed tomography (PET-CT) revealed a solitary mass in the upper lobe of the right lung, with uneven radioactivity uptake and a maximum standardized uptake value of 5.6. The greyish-yellow specimen obtained following thoracoscopic resection was covered with small multi-nodulated structures and consisted of soft tissue. Hematoxylin and eosin staining revealed spindle-shaped malignant tumor cells. Immunohistochemistry indicated these tumor cells were CD99 and BCL-2-positive. Furthermore, the FISH test revealed synovial sarcoma translocation genetic reassortment, which confirmed the diagnosis of SS.

CONCLUSION

PPSS is extremely rare and tends to be misdiagnosed as many primary pulmonary diseases. PET-CT, histologic analysis, and FISH tests can be used to differentiate PPSS from other diseases. Surgical resection is regularly recommended for the treatment of solitary PPSS and is helpful for improving the prognosis.

A Pulmonary Zebra: Adult Primary Pulmonary Synovial Sarcoma

Primary pulmonary synovial sarcoma (PPSS) is an extremely rare tumor, with approximately 50 cases being reported in the English literature (Golota et al., 2018). Difficulties are often encountered in the diagnosis of PPSS as it can be confused with other spindle or round cell tumors, such as fibrosarcoma, hemangiopericytoma, mesothelioma, sarcomatoid carcinoma, or metastatic sarcomas. PPSS was first described by Zeren et al. in 1995. We present a case of PPSS in a 41-year-old woman, who complained of progressive dyspnea and left-sided chest pain.

Primary Pulmonary Round Cell Sarcomas: Multiple Potential Pitfalls for the Pathologist

Primary sarcomas of the lung are extremely uncommon. A diverse group of round cell sarcomas has been reported to originate in this location, including Ewing sarcoma, desmoplastic small round cell tumor, rhabdomyosarcoma, and poorly differentiated synovial sarcoma. The rarity of these tumors presents a potential pitfall; without careful study, they may easily be misidentified as the significantly more common poorly differentiated carcinoma. While histomorphology is a key aspect of correctly identifying a sarcoma, ancillary testing has become increasingly important in making a definitive diagnosis, as more and more recurrent genetic alterations are discovered and new entities are defined. We present three cases of primary round cell sarcomas of the lung that proved diagnostically challenging, describe the features and ancillary testing that led to the correct diagnoses, and discuss classic and evolving entities among sarcomas with round cell morphology.

Imaging findings of primary pulmonary synovial sarcoma with secondary distant metastases: A case report

BACKGROUND

Synovial sarcoma (SS) accounting for 6%-10% of primary soft tissue malignancies mainly occurs in deep soft tissue adjacent to joints of the limbs. Primary pulmonary SS (PPSS) is rare and has a poor prognosis. Cases of secondary distant metastases of PPSS occur rarely and there is a lack of corresponding imaging reports. We summarized the imaging findings of PPSS with multiple metastases confirmed by surgery and pathology, and shared valuable information on PPSS.

CASE SUMMARY

A 43-year-old female patient had a solid space occupying lesion in the right upper lobe of the lung. The results of a hemogram, erythrocyte sedimentation rate (ESR) and tumor markers were all within the normal range, tuberculin skin test (5 TU PPD) was negative (-). Chest computed tomography examination showed similar round soft tissue density in the posterior segment of the right upper lobe. Thoracoscopic-assisted wedge resection of the right upper lobe of the lung, right upper lobe resection and lymph node dissection were performed. Nine months after surgery, ultrasound examination showed multiple metastases on the chest wall and kidney.

CONCLUSION

PPSS is a rare malignant lung tumor with strong invasiveness, early distant metastasis and poor prognosis. There are very few imaging reports. PPSS is often manifested as irregular tumor and calcification, and the metastases have extremely low echo on ultrasonography. Contrast-enhanced ultrasound indicates that the arterial phase of tumor metastases shows rapid centripetal high enhancement, manifested as “fast forward and fast regression”.

Primary Pulmonary Synovial Sarcoma in a 49-Year-Old Male

Sarcoma is a malignant tumor arising from the mesenchymal tissues such as striated skeletal and smooth muscles, adipose tissue, bone, cartilage, and synovial tissue. The synovial subset of primary pulmonary sarcoma is very rare and is only described in a handful of cases. Our case describes the diagnostic approach and treatment regimen for a 49-year-old male with no significant past medical history. The diagnosis of a primary pulmonary synovial sarcoma was made through the use of endobronchial ultrasound (EBUS), transbronchial needle aspiration (TBNA), histologic analysis, and immunostaining. The treatment utilized a multimodal approach including resection, chemotherapy, and radiotherapy.

A rare case of pleuropulmonary synovial sarcoma of the chest wall: A case report and a literature review

Pleuropulmonary synovial sarcoma is a subtype of synovial sarcomas that commonly arises from the chest wall, pleura, lungs and the heart. They are extremely rare, with only a few cases reported in the literature. It usually affects young and middle-aged adults with no gender predilection. Chest radiographs usually show a pleural-based mass, parenchymal consolidation, or a near complete opacification of the hemithorax. On contrast-enhanced CT, synovial sarcomas of the chest wall typically appear as a well-defined, heterogeneously enhancing mass with bone destruction and infiltration of chest wall musculature. MRI usually demonstrates a heterogeneous mass with areas of both high and low T1 signal intensities representing areas of hemorrhage and necrosis. We report a case of a 39- year old African male patient who presented to our hospital complaining of chest pain of 4 months duration. The plain chest radiograph showed complete opacification of the left hemithorax. Contrast-enhanced CT and MRI were then performed revealing a large left-sided heterogeneous mass. PET-CT demonstrated avid FDG uptake in the solid components of the mass with no evidence of distant metastasis._. An ultrasound-guided biopsy was performed, and histopathology revealed a locally advanced primary synovial sarcoma of the chest wall. Treatment consisted of neoadjuvant chemotherapy followed by surgical resection.

BRAF V600E mutation is a potential therapeutic target for a small subset of synovial sarcoma

Synovial sarcoma (SS) is an aggressive tumor that most often affects the deep soft tissues in young adults. Intrathoracic SS is rare and is associated with poor outcome, highlighting the urgent need for a novel therapeutic strategy. In the process of clinical sequencing, we identified two patients with intrathoracic SS harboring the BRAF V600E mutation. The patients were women aged 32 and 23 years, and both presented with SS18-SSX2-positive monophasic SS in the thoracic cavity. BRAF V600E mutations were detected by next generation sequencing, and validated immunohistochemically by diffuse intense positivity to BRAF V600E mutation-specific antibodies. The phosphorylated ERK (pERK) immunohistochemistry result was also positive. One patient received a combination therapy of dabrafenib and trametinib, which led to tumor shrinkage. However, the tumor growth progressed 7.5 months later with an additional NRAS Q61K mutation. Immunohistochemical screening of 67 archival SS tumor samples failed to identify additional samples with BRAF V600E mutation. However, 32% of BRAF V600E-negative cases was positive for pERK, and one of the six tumors showing the highest pERK expression harbored an FGFR2-activating mutation. This is the first report of targetable BRAF mutation in a small subset of SS. Our study suggests involvement of the mitogen-activated protein kinase pathway and the potential clinical implication of BRAF mutation screening in SS.

Primary pulmonary synovial sarcoma with calcification: A case report

The lung is the organ most commonly affected by primary synovial sarcoma. Intratumoral calcification is less common in this organ versus soft tissue. Meanwhile, the presence of calcification in a lung nodule reduces the risk of lung cancer. Here, we report a case of pulmonary synovial sarcoma which manifested as a nodule with calcification, depicted on computed tomography (CT). A 52-year-old asymptomatic male was referred to Saitama Medical University International Medical Center and CT revealed a well-defined nodule (1.8 cm), with punctate and eccentric calcification in the right lower lobe. Enhanced CT and 18F-fluorodeoxyglucose positron-emission tomography suggested a malignant tumor, and surgery was performed. Histology provided a preliminary diagnosis of monophasic spindle-cell synovial sarcoma with hyalinized collagen bands and calcifications. Genetically, the presence of the SYT-SSX2 fusion gene was consistent with the features of this disease. We conclude that primary pulmonary synovial sarcoma should be listed as a differential diagnosis for solitary pulmonary nodules with calcification.

The role of 18F-FDG PET/CT in soft tissue sarcoma

INTRODUCTION

Soft tissue sarcomas (STS) are highly fluorine-18-fluorodeoxyglucose (F-FDG)-avid tumours. PET seems to be effective for the assessment of the extent of disease. However, the use of PET to stratify STS into different risk histotypes still remains controversial. Our aim was to evaluate F-FDG uptake in different STS types and to assess the prognostic value of the maximum standardized uptake value (SUVmax).

PATIENTS AND METHODS

We reviewed 50 adult patients with primary high-grade STS of the extremities with a preoperative PET. Overall survival and local recurrence were analysed.

RESULTS

The mean SUVmax was 12.9 (range: 2.2-33.4). All cases of myxoid liposarcoma and all cases of synovial sarcoma had SUVmax of less than 10.3. A better overall survival and local recurrence were observed in patients with SUVmax of less than 10.3 (P=0.005 and 0.046, respectively).

CONCLUSION

SUVmax seems to be specific among different STS histotypes. PET does not seem to be useful in myxoid liposarcoma as well as synovial sarcoma as these tumours seem to have a low uptake of glucose. SUVmax might also be included as a prognostic factor.

Primary Pleuropulmonary Synovial Sarcoma on Fluorodeoxyglucose Positron Emission Tomography-Computed Tomography Scan

Primary pleuropulmonary synovial sarcoma, a mesenchymal tumor of lung and pleura, is very rare and highly aggressive condition among the primary lung malignancies. As role of fluorodeoxyglucose positron emission tomography-computed tomography (FDG PET-CT) has been established in lung malignancies in terms of staging, restaging, biopsy guidance, and treatment response evaluation, there is also role of FDG PET-contrast-enhanced CT (CECT) to raise suspicion or increase confidence in reporting of sarcomatous lung malignancy by studying characteristics of CECT scan features. We present a case of a 57-year-old female patient having large lung mass, who underwent FDG PET-CT scan and findings raised strong suspicious of noncarcinomatous pattern of lung mass and may have sarcomatous primary lung malignancy which was later proven on histopathological and immunohistochemistry report.

Diagnostic value of endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) in solitary mediastinal, hilar lymphadenectasis, or peribronchial lesions: Six cases reports and review of literature

BACKGROUND

Patients with isolated mediastinal or hilar lymphadenopathy, or peribronchial lesions, are common presentation to clinicians. Due to the difficulty in tissue sampling, the pathological diagnosis is not so easy. Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is an established, highly effective, minimally invasive technique for sampling. The current study was conducted to investigate the value of EBUS-TBNA in patients of solitary mediastinal, hilar lymphadenectasis, or peribronchial lesions.

METHODS

Six patients with different pathological results diagnosed via EBUS-TBNA were retrospectively analyzed in this study.

RESULTS

All 6 patients of solitary mediastinal, hilar lymphadenectasis, or peribronchial lesions underwent conventional flexible bronchoscopy before EBUS-TBNA, but only EBUS-TBNA was helpful for the finally definite diagnosis. No complication was observed.

CONCLUSION

EBUS-TBNA is a safe and highly effective diagnostic procedure for both benign and malignant diseases, especially for patients with solitary mediastinal, hilar lymphadenectasis, or peribronchial lesions.

Primary pleuropulmonary and mediastinal synovial sarcoma: a clinicopathologic and molecular study of 26 genetically confirmed cases in the largest institution of southwest China

BACKGROUND

Primary pleuropulmonary and mediastinal synovial sarcomas (PPMSSs) are extremely rare. The authors present the largest series in an Asian population.

METHODS

Between 2000 and 2015, 26 genetically confirmed PPMSSs were included. The clinicopathologic features of all of the cases were reviewed. Immunohistochemical staining was carried out using the following antibodies: TLE1, cytokeratin (AE1/AE3), EMA, CD99, Bcl-2, CK7, CD34, S-100 protein, and Ki-67. The chromosomal translocation t(X;18)(p11.2;q11.2) was detected by fluorescence in situ hybridization (FISH) and reverse transcription polymerase chain reaction (RT-PCR). We compared the clinical, pathologic, immunohistochemical, and molecular features of this series with that of the previous series and soft tissue synovial sarcomas.

RESULTS

This series included 17 males and nine females. The median age was 36.5 years (range, 16-72 years). The tumors involved the lung (76.9 %), pleura (15.4 %), and mediastinum (7.7 %). The median tumor size was 6 cm (range 2.3 ~ 24 cm). The majority of the tumors were well-circumscribed. The tumors were classified as monophasic (84.6 %), biphasic (3.8 %), and poorly differentiated (11.5 %) types. The tumors were graded as French Federation of Cancer Centers (FNCLCC) grade 2 (62.5 %) and FNCLCC 3 (37.5 %). Diffuse immunostaining for TLE1, BCL-2, and CD99 was identified in 91.7, 95.7, and 56.0 % of the tumors, respectively. Focal positivity was seen with EMA (84.6 %), CK7 (55.6 %), cytokeratin (AE1/AE3) (68.0 %), CD34 (5.0 %), and S-100 protein (21.7 %). A high Ki-67 index (≥10 %) was observed in 91.3 % of the tumors. The fusion transcripts included SS18-SSX1 (15/22, 68.2 %), SS18-SSX2 including variants (6/22, 27.3 %), and SS18-SSX4 (1/22, 4.5 %) fusions. The remaining four cases showed positivity for SS18 rearrangement by FISH. Surgical excision of tumors or lobectomy were performed in 20 patients, and seven of the patients underwent adjuvant therapy. Clinical follow-up was available in 73.1 % cases, with a median follow-up of 12.0 months. The median survival time was 14.5 months. Tumor resection (p = 0.024) and no residual tumor (p = 0.004) were associated with an improved overall survival time.

CONCLUSIONS

PPMSS is a highly aggressive neoplasm. Extensive surgical resection of the tumor and more effective adjuvant therapy should be advocated. PPMSS must be differentiated from similar diseases.

Primary pulmonary synovial sarcoma presenting with a large lump mass in the left upper mediastinum: A case report

Primary pulmonary synovial sarcoma is a rare lesion that occurs in 0.5% cases of lung malignancies. Chest computed tomography (CT) reveals a heterogeneously enhancing mass in the lobe or hilum of the lungs, frequently calcified and with pleural invasion. Involvement of the mediastinum in the course of primary pulmonary synovial sarcoma, in particular detection of a large mass in the mediastinum as the sole initial imaging manifestation, is extremely rare, which may contribute to a delayed diagnosis or misdiagnosis. The present case report describes an extremely rare case of a patient with primary pulmonary synovial sarcoma presenting with a large mass in the left upper mediastinum. A 59-year-old patient was admitted to the Department of Respiratory Medicine of Taizhou People's Hospital in May 2014, complaining of a persistent cough and blood sputum for 2 weeks. Following admission, a chest CT showed a large mass in the left upper mediastinum. Thoracoscopy was performed and revealed that the left pulmonary artery was engulfed by the mass, and thus surgical resection of the tumor was abandoned. The patient was definitively diagnosed with primary pulmonary synovial sarcoma following the histopathological and immunohistochemical analysis of biopsy specimens obtained via thoracoscopy. Following the final diagnosis, the patient was transferred to the Department of Oncology for chemotherapy treatments with ifosfamide and doxorubicin. Unfortunately, no partial regression was achieved after two rounds of chemotherapy, and the patient was lost to follow-up 3 months after the diagnosis was confirmed. The present case may promote the consideration of primary pulmonary synovial sarcoma in the differential diagnosis of patients who present with a large mass in the mediastinum.