Pediatric Synovial Sarcoma

  • Etiology: Malignant soft tissue tumor
  • Imaging Radiograph: Look for calcification
  • Imaging US: Use to confirm solid versus cystic when in doubt
  • Imaging MRI:
    — Well circumscribed mass that can look like cyst or ganglion
    — Can be remote from joints
    — Can contain fluid-fluid levels and calcification
  • DDX:
  • Complications: Metastasis to lung
  • Treatment:
  • Clinical: Second most common soft tissue tumor after rhabdomyosarcoma

Radiology Cases of Synovial Sarcoma

MRI of synovial sarcoma of groin
Axial (above right) and sagittal (below right) T2 MRI of the pelvis shows a well circumscribed soft tissue mass that is hyperintense compared to muscle and not clearly connected to any joint and that has some surrounding edema. Axial T1 MRI without contrast (above left) and axial T1 MRI with contrast (below left) show the mass to enhance homegenously.