Atypical organizing haematoma/seroma following treatment for soft tissue sarcoma

Fluid collections of lymph (seromahygroma) or blood (haematoma), which progressively undergo organization, may develop at the site of soft tissue sarcoma excision. These lesions are more common in the lower extremity at the junction between the subcutaneous fat and the fascia. Radiation therapy contributes to their formation by rendering the soft tissues non-compliant and therefore creating a potential space for fluid collection. Due to atypical magneticresonance imaging findingsand progressive increase in size, these lesions may be surgically explored to exclude recurrence or radiation-induced sarcoma.