Large inguinal synovial sarcoma mimics a vascular lesion: A case report and literature review

INTRODUCTION: Synovial sarcoma (SS) is one of soft tissue sarcomas (STS), characterized by t(X;18)(p11;q11) chromosomal translocation. Clinical diagnosis of SS in groin is difficult owing to rarity and various manifestations. We reported a rare and interesting case of inguinal biphasic SS with initial impression of a vascular lesion. PRESENTATION OF CASE: We reported a 72-year-old man who presented with a right inguinal progressively enlarged mass for 5 years. The mass became ulcerative with active bleeding after blunt trauma. Computed tomography (CT) showed a large heterogeneous tumor with focal vivid enhanced area, and an inguinal vascular lesion was impressed. Angiography revealed faint tumor stain without contrast extravasation or aneurysm lesion. Surgical resection of the tumor was performed. Final pathology and fluorescence in situ examination (FISH) demonstrated biphasic SS with SS18 gene rearrangement. No evidence of recurrence after one-year follow-up. DISCUSSION: SS constitutes 5%–10% of STS. The most primary sites are extremities (68.7%) and trunk (15.7%). Treatment options for SS include surgery, chemotherapy, radiotherapy, targeted therapy, and novel therapies. In our case, the initial impressions of large inguinal tumor were hematoma or pseudoaneurysm. Preoperative angiography assisted in differentiating the lesion, evaluating tumor vessels, and preventing bleeding by embolization. Our patient recovered satisfactorily after surgical excision without major complications. CONCLUSION: Primary inguinal SS is an extremely rare tumor which can present as a vascular lesion. Diagnosis is confirmed by pathology and FISH exam. Further studies are required to determine the manifestation and management of SS.