Introduction:The skeleton is the most common target of metastatic disease, after lungs and liver. Humerus is the third most common location for a bone metastasis. Pathologic fractures occur as a response to the compromised physiology of the bones, which has as a result poor mechanical properties due to the underlying lesion. Methods and Materials:A 59year-old woman with diagnosed and under treatment lung cancer arrived at the outpatient orthopaedic clinic due to chronic pain (three weeks) and inability to lift her right arm. The onset of pain was gradual. Radiological tests showed a fracture in the proximal third of the humerus and a lytic lesion. Results:The patient was treated with internal fixation with a locking plate, broad abrasion and ablation of the lytic lesion and cement infusion. The patient was mobilized without limitations, other than avoidance of loading, post-operatively. Conclusion:Pathological fractures are a common complication of bone metastases. Life expectancy in patients with bone metastases has been extended due to the progress in chemotherapy, radiotherapy, and other oncological therapies. At pathological fractures of the humeral shaft, the abrasion of the lytic lesion and the infusion of cement, after internal fixation, creates a more stable fixation of the fracture and gives the patient a better quality of life being able to use the arm. According to current bibliography, the use of PMMA limits the spread of cancer cells.