Learning Radiology xray montage

Synovial Sarcoma

  • Middle-aged and older adults
  • Most frequent presentation: painful swelling of the knee
    • Predisposition for lower extremity
  • It is a malignancy
  • Can occur at any age
    • Usually third and fourth decades
  • Usually are extra-articular
  • X-ray
    • Soft tissue mass near articular surface
    • Frequently, spherical and lobulated in shape
    • 20-30% calcify
    • About 1/3 have adjacent erosion of bone
      • Look for erosions on both sides of a joint
    • Osteoporosis is common secondary to disuse
      • DDX from pigmented villonodular synovitis where there is rarely osteoporosis
  • Can metastasize to lungs
    • Mets to lungs almost never calcify
  • Mets to bone itself very rare
  • Prognosis is poor
  • Benign variety occurs in the joint capsule around knee
  • DDX:
    • Tumoral calcinosis

Synovial Sarcoma. Frontal radiograph of the foot demonstrates a heavily calcified
 lesion which is arising from the dorsum of the foot between the 2nd and 3rd metatarsals (white arrows)..

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