Synovial sarcoma presenting as an avascular mass: radiologic-pathologic correlation.

Area of Science:

• Oncology
• Radiology
• Pathology

Background:

• Synovial sarcoma is a soft tissue malignancy common in young adults, originating from mesenchymal tissue with epithelial differentiation.
• Characteristic MR imaging findings include heterogeneous masses with variable signal intensities and prominent enhancement, reflecting high vascularity.

Observation:

• A case of high-grade synovial sarcoma presented with absent vascularity and enhancement on contrast-enhanced MR imaging.
• This imaging finding was observed despite the presence of enhancement in metastatic lymph nodes.

Findings:

• The lack of vascularity on MR imaging was attributed to extensive hyalinization within the sarcoma.
• Hyalinization led to a paucity of small-caliber vessels, altering the typical vascular appearance.

Implications:

• This case highlights an unusual presentation of synovial sarcoma, challenging the assumption of universal hypervascularity.
• Radiologists should consider hyalinization as a potential cause for avascularity in synovial sarcoma, especially when evaluating contrast-enhanced MR images.