Background: Synovial Sarcoma (SS) is an infrequent malignant tumor that typically arises in the deep soft tissues of the extremities. It originates from mesenchymal cells with synovial differentiation. While SS rarely infiltrates the vagus nerve, there have been no documented cases reported. The slow growth and nonspecific early symptoms, signs, and imaging findings associated with SS often result in misdiagnosed cases.
Case presentation: A 49-year-old woman presented with a persistent dry cough lasting 17 months, a neck mass persisting for 5 months, and hoarseness for 20 days. Despite long-term treatment with inhaled cortisol hormone, her cough did not improve. Contrast-enhanced CT/MRI scans of the neck revealed that the tumor originated from nerves. Intraoperative cytopathology suggested that the tumor was a benign spindle cell tumor of neurological origin, leading to neurectomy. Postoperative immunohistochemistry demonstrated Ki-67 positivity in approximately 10% of the tumor, indicating that it should be managed as a borderline lesion. A wide-margin resection of the tumor was performed with the patient's informed consent again. Postoperative pathology revealed the presence of SS of the right vagus nerve. Fluorescence in situ hybridization was conducted, which confirmed the presence of the ectopic SS18 gene.
Conclusions: We present a unique case of SS affecting the vagus nerve, resulting in cough and hoarseness. Accurate identification of SS involving the vagus nerve necessitates comprehensive examination,including histopathological, immunohistochemical, and molecular cytogenetic analyses. Considering the associated symptoms is crucial to minimize the risk of overlooking or misdiagnosing such conditions.