Primary Malignant Synovial Tumor in the Mediastinum

Shreyas Bellur,Sreekar Balasundaram

doi:10.7759/cureus.20076

Abstract

Primary mediastinal synovial sarcomas constitute a rare subset of mediastinal tumors. The diagnosis is often delayed at the time of presentation impacting the five-year survival rate due to its highly aggressive natural history. We report a 22-year old female with a monophasic variant of the primary mediastinal synovial sarcoma.A 22-year-old female, with a two-month history of productive cough, fever, breathlessness, was referred to our center in view of persistent right-sided hydropneumothorax despite multiple thoracocenteses. Examination revealed reduced right-sided air entry with a succussion splash. Imaging suggested a well-defined cystic lesion with fluid, air foci, and multiple septations. A provisional diagnosis of a ruptured hydatid cyst was made and exploratory thoracotomy was planned. Intraoperatively, a well-defined cystic lesion with 350 mL of hemorrhagic fluid, densely adherent to the lung and diaphragm, was found. The biopsy revealed a monophasic spindle cell variant of the primary synovial sarcoma. Follow-up positron emission tomography (PET) on postoperative day 20 showed no residual disease and evidence of metastasis. However, the patient was lost to follow up following one cycle of chemotherapy with ifosfamide.Primary mediastinal synovial sarcomas are aggressive tumors that warrant an early diagnosis for prompt treatment. They usually present with non-specific respiratory symptoms. The gold standard of diagnostic modalities is a molecular panel looking for the translocation - t(X;18)(p11;q11). However, in low-middle income countries, a biopsy may be more practical, as they are cost-effective. The treatment is surgical resection, with combined chemotherapy and radiotherapy if metastases are present.Our case emphasizes the early detection of this lesion, its mimicry with other lesions, and the impact of early diagnosis.

Highlights

Primary synovial sarcomas are aggressive malignant tumors that are a subtype of soft tissue sarcomas
We present a case of a 22-year-old female with primary mediastinal synovial sarcoma (PMSS) mimicking a hydatid cyst
Fluid cytology showed paucicellular cyst fluid with a few lymphocytes and biopsy findings were consistent with monophasic spindle cell variant of the synovial sarcoma (Figure 4)

Summary

Introduction

Primary synovial sarcomas are aggressive malignant tumors that are a subtype of soft tissue sarcomas. She reported no hemoptysis, loss of weight, and history of tuberculosis. Α-fetoprotein and β-human chorionic gonadotropin (β-HCG) were within normal limits After informed consent, she underwent surgery, and intraoperatively, we found a thick fluid-filled cyst with solid areas and approximately 350 mL of hemorrhagic fluid (Figure 3). Fluid cytology showed paucicellular cyst fluid with a few lymphocytes and biopsy findings were consistent with monophasic spindle cell variant of the synovial sarcoma (Figure 4). Chest x-ray showed complete expansion of the right upper lobe, and PET scan showed no evidence of residual disease or metastasis. She was advised chemotherapy, but after one cycle with ifosfamide, was lost to follow up

Discussion

Conclusions

Findings

Disclosures