**6. Biopsy**

Biopsy of a bone neoplasm is a fundamental and final part of the diagnostic evaluation, with the objective of obtaining sufficient material for the histological diagnosis with minimal morbidity, limiting potential tumor spread, and not harming the surgical treatment [48, 49]. A surgeon experienced in the treatment of bone neoplasms or in Ref. centers must perform the biopsy in order to minimize the known complications of the method. A study showed that biopsies performed by other surgeons present up to 18% of diagnostic errors; 10% present as poorly planned biopsies or with insufficient material; 9% have some skin, bone, or soft tissue complication; 10% influenced the course of the disease and 3% resulted in unnecessary amputations [50]. Pathological fractures (**Figure 6**), are not common after biopsy procedures but may occur in about 10–25% of procedures performed in patients with osteosarcoma, 5% in chondrosarcomas, and 8–9% in Ewing's sarcomas (**Figure 7**) [51].

### **Figure 6.**

*(A) patient with an osteolytic lesion on the left femoral shaft, (B) fluoroscopy image of femur fracture during biopsy procedure, and (C) stabilization with external fixator was performed (patient with liver cancer).*

### **Figure 7.**

*(A) patient with a lytic lesion in the diaphysis of the right femur and an onion skin periosteal reaction, (B) extension femoral lesion with the presence of skip metastasis, (C) evolution to pathological fracture after biopsy procedure, and (D) stabilization with plaster cast.*

There are two types of biopsy: open and percutaneous. Although for a long time the incisional (open) biopsy was considered the gold standard, the minimally invasive techniques (percutaneous – fine needle aspiration and core needle biopsy) have presented similar results [48, 49].
