Radiotherapy for this type of tumor would be possible in principle but is not indicated in infancy due to its age and severe late sequelae such as possible cartilage and bone deformities (6). Earlier surgery would have increased the probability of primary R0 resection and reduced the probability of possible metastasis. However, we consider the R1 resection achieved after initial surgery without neoadjuvant therapy to be acceptable and the only option due to the size of the tumor at the time of excision. The complication-free second resection with acceptable tumor-free margins and complete functional preservation of the affected extremity support our therapeutic decision. The last MRI control 9 months after the second resection showed no renewed tumor growth.
Conclusion:
1.    Children with unclear lump should be referred for further diagnostic to specialized centers of pediatric oncology.