Case report: Synovial sarcoma of the axilla with axillary nerve involvement

Case presentation: A 42-year-old woman patient noticed a painless mobile lump in her left axilla about six months prior. Her biopsy revealed synovial sarcoma. The mass did not change in size over this period. It was associated with increased pain and numbness involving her left arm. No adjacent lesions or regional lymph nodes were noted. No abnormality was observed on neurovascular examination. Aside from a mild decrease in superficial touch sensation in her left arm. The magnetic resonance showed well-defined oval-shaped heterogeneous soft tissue mass near the axillary nerve with no clear encasement. The lesion measured 3.6 × 3 cm in axial diameter. Based on the radiological and the histopathological findings, the mass excision was pointed out. The surgical procedure was carried out. The tumor capsule was dissected away thoroughly with axillary nerve injury. In her postoperative course, she lost her axillary nerve function with left shoulder abduction weakness. Her final histopathology analysis confirmed a synovial sarcoma with high-grade and positive margins. The patient received postoperative radiation with 50 Gy. Upon follow-up, five months after radiation therapy, no clinical or radiological recurrence was evidenced.” Discussion: Our patient represents a unique case of axillary synovial sarcoma arising from within the axillary nerve. This combination adds to the challenge in approaching such tumors which might significantly affect survival and function. However, this localization represents a sporadic occurrence. Therefore, the role of neoadjuvant chemotherapy was discussed with the oncology team. Recognizing the size and location of the lesion, together with the controversial role of chemotherapy in the treatment of synovial sarcoma, led us to the decision that neoadjuvant chemotherapy would not bring out benefits for this patient. Hence, the patient received postoperative radiation based on the high grade of the tumor and the postoperative histopathological findings of positive resection margins. Final comments: Our case report represents an occurrence of synovial sarcoma in the axilla with involvement of the brachial plexus. When radiological findings suggest soft tissue sarcoma of the axilla, we strongly recommend the surgical procedure for lesion’s excision with negative margins. The radiation therapy should be considered for tumors with positive or uncertain margins, deep lesions that are challenging for surgical resection and the location in which local recurrence would require amputation.