Conventional intramedullary osteosarcoma has a predilection for the metaphyseal region of the long bones. A common clinical feature is localized pain that frequently begins post-injury and waxes and wanes over time. The most important finding on physical examination is a soft tissue mass, which is frequently large and tender to palpation [4]. Laboratory evaluation is usually normal, except for elevations in the alkaline phosphatase (in approximately 40 %), lactate dehydrogenase (in approximately 30 %), and erythrocyte sedimentation rate [5, 6].

The staging assessment includes magnetic resonance of the entire length of the affected bone, computed tomography of the chest, bone scan, and/or positron emission tomography (PET) scan. In the absence of symptoms, images of the abdomen are not required because of the extreme rarity of metastasis in this location. It usually spreads hematogenously, and the main site of metastasis is the lung. On presentation, between 10 % and 20 % of patients have demonstrable macrometastatic disease.

The mainstay of treatment is tumor resection surgery, preferably with wide margins. However, it is always necessary to consider limb preservation in patients with localized disease.

After introducing chemotherapy, the survival in patients with localized high-grade osteosarcoma has improved. Chemotherapy comprises two phases: neoadjuvant (evaluation of the in vivo response and eradication of the micrometastases) and adjuvant. Generally, chemotherapy is administered pre- and postoperatively, and the extent of the histological response to preoperative chemotherapy predicts survival. According to the Huvos classification for tumor necrosis osteosarcoma, tumors with improved responsivity to chemotherapy (degrees III and IV) have a better prognosis.

Initially, postoperative chemotherapy was used, and the 5-year survival rates increased from <20 % to between 40 % and 60 % in the 1970s [8]. Two subsequent randomized studies conducted in the 1980s reported on high-dose methotrexate plus doxorubicin, bleomycin, cyclophosphamide, and dactinomycin and either vincristine or cisplatin. The study demonstrated a significant relapse-free and overall survival benefit for adjuvant chemotherapy that persisted in the long-term [6, 9–11]. However, these trials were limited in size, and the survival benefits were modest.

There is no worldwide consensus on a standard chemotherapy approach for osteosarcoma. The majority of regimens in adjuvant chemotherapy use doxorubicin (75 mg/m²) and cisplatin (100 mg/m²) every 21 days, with or without high-dose methotrexate (8 g/m²), which is followed by rescue leucovorin before each cycle. In adults aged >30 years, the literature emphasizes the use of protocols that do not contain high-dose methotrexate because of the uncertainty of its real value in the cure rate in localized disease (according to pediatric protocols), and there are issues in terms of severe toxicity in adults [12–15].