Sarcomasdown arrow


Ewing sarcoma



Disease Spread

Ewing sarcoma (ES):

  • Invades locally with bone destruction, involvement of adjacent soft tissues and intramedullary spread.
  • Ewing sarcoma of bone rarely spreads to adjacent lymph nodes. This is more commonly seen in a primary Ewing sarcoma arising in soft tissues (extra-osseous Ewing sarcoma).
  • Distant metastases - almost always hematogenous are common  
    • Most cases of ES have microscopic (clinically undetectable) spread at diagnosis. 
    • 25 - 30% of patients have clinically detectable metastatic disease at presentation. 
  • If Ewing sarcoma occurs in a location (parameningeal or spinal) where there is invasion of the CSF pathways, leptomeningeal spread may occur.


Summary of ES routes of spread:

  • Tumor infiltrates bone marrow and adjacent soft tissue
  • Plain films show a permeative destructive lesion of bone
  • The periosteum is typically displaced by the underlying tumor, resulting in the sign of Codman triangle
  • An associated soft tissue mass is typical
  • New bone formation is typical



  • If ES is treated without systemic chemotherapy, at least 90% of patients will develop distant metastases
  • Common sites for metastases: lungs, bone marrow, and bones
  • Metastases to lymph nodes are rare
  • Leptomeningeal spread is possible for tumors associated with CSF pathway invasion



Most common sites for ES metastatic disease:


Proportion of Metastases


40 - 50%


25 - 30%

Bone marrow



The CT below shows a pulmonary metastatic deposit in a young woman with ES (#1 - the small round mass in the left costophrenic sulcus).




Back to top