Background/aims The differential diagnosis of round cell tumors of bone (RCTB), Ewing sarcoma, smallcell osteosarcoma, mesenchymal chondrosarcoma, osteoblastoma, chondroblastoma, primary bone lymphoma, and multiple myeloma still remains a challenge. Given the significant differences in treatment, an accurate diagnosis is crucial. This study aimed to evaluate some histochemical and immunohistochemical criteria of RCTB. Participants and methods Periodic acid-Schiff (PAS), CD99, CD138, ... إقراء المزيد