Osteosarcoma is a malignant tumor of the bone, most commonly found in adolescents and young adults. The most frequent sites are the distal femur, the proximal tibia, or the proximal humerus. Early-stage patients often experience lung metastases, which are quite common. Initially, there are no symptoms; however, as the disease progresses, symptoms such as lumps, significant pain especially at night, increased local skin temperature, dilated veins, and weight loss may appear. At this stage, radiographic examinations are imperative to identify the tumor presence, indicated by findings such as a Codman triangle or sunray appearance, which are suggestive of osteosarcoma, though confirmation through pathology is essential. Furthermore, comprehensive body scans are necessary to check for metastases. Early-stage lung metastases might not show symptoms, but as the disease advances, symptoms like coughing, coughing up blood, and pleural effusion, possibly bloody, may develop. Severe cases can lead to respiratory difficulties and cachexia. Early detection and treatment, combined with postoperative chemotherapy, can lead to a five-year survival rate of over 50%. However, the disease is often diagnosed in its intermediate to late stages due to the absence of early symptoms, making it challenging to detect.