YO28 - Successful Multimodal Treatment of an Advanced Case of Axillary Synovial Sarcoma

Case summary

Synovial sarcomas are aggressive and rare mesenchymal tumors that frequently recur and metastasize. It occurs in adolescents and young adults, and arises around joints in the lower extremities. Our patient is a 19-year old woman who presented with a six month history of an enlarging right axillary mass. She eventually had difficulty abducting her right arm, and had occasional paresthesia over her right arm and shoulder. Core needle biopsy revealed a spindle cell neoplasm, with histomorphology and immunohistochemical staining favoring a synovial sarcoma. Molecular testing by PCR for SYT-SSX fusion was qualitatively positive, confirming the diagnosis. Magnetic resonance imaging revealed a complex, insinuating mass measuring 11.0 x 10.1 x 11.0cm with sternal attachments at the pectoralis muscles and infero-posteriorly displaces the right subclavian to axillary artery. Vascular doppler studies revealed intact flow up to the distal arterovenous segments of the arm. With the goal of a limb-sparing surgical plan, the multidisciplinary team recommended neoadjuvant chemotherapy, then subsequent neoadjuvant radiation. She received and tolerated three cycles of Epirubicin (75mg/m2 on day 1) and Ifosfamide (1.8mg/m2 on days 1-5) with recommended MESNA doses as well as prophylactic GCSF support. Notably, the patient reported ease of arm abduction and disappearance of paresthesia. She then received radiation therapy at 50Gy. Upon re-evaluation, her chest MRI revealed that the tumor had only regressed by 9.1% by RECIST criteria. After six weeks, she then underwent a wide resection of the right axillary mass, revealing a 9.5cm mass, marginally excised at the anterior surface, but with negative margins in all other sections. Three lymph nodes were negative for tumor and no lymphovascular invasion was noted. After 8 weeks, radiation boost to the right axilla was delivered via IMRT at 2000cGy in 10 fractions upon recommendation of the multidisciplinary team. The patient's latest surveillance chest and abdominal MRI reveals no evidence of disease. She is due to for surveillance scans and TSH monitoring every 3-6 months for two years. A breast MRI, approximately eight years after she received radiation is also planned for breast cancer screening.

Clinical trial identification

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