A 15-year-old boy has developed pain in the area of his left knee joint. Objectively: thigh soft tissues in the painful area are infiltrated, joint function is reduced. X-ray: there is a focus of destruction in the left distal femoral metaphysis, with periosteum detachment and formation of Codman triangle in the bone cortical layer at the margin of the defect. Chest X-ray reveals numerous microfocal metastases. What pathology is the most likely to cause such presentation?