Background

Osteosarcoma is a highly malignant and potentially destructive tumor. It is also the most common primary malignant tumor found in the long bones. Still, osteosarcoma is rare. That most cases of osteosarcoma that can be classified as low–grade develop in the bones of the mandible, indicating that there may also be histological differences between the sites.

Case Report

An 18–year–old male patient visited a private dentistry office with complaints of increased volume in the region of the mandible. Periapical radiographs were requested. After evaluation, endodontic therapy was indicated for the affected teeth. Endodontic therapy was unsuccessful. Next, pulp vitality testing was performed on the affected teeth, and cone beam computed tomography was requested. This exam allowed for a diagnostic hypothesis of a malignant lesion. Because of this hypothesis, an incisional biopsy was performed, and the histopathological diagnosis was that of low–grade malignant osteosarcoma. The surgical treatment proposed was the partial resection of the anterior region of the mandible with surgical margins around the lesion for subsequent reconstruction. Because of the low grade of malignancy, complementary treatment with radiation therapy or chemotherapy was not indicated. Long–term follow–up care is necessary, with annual scans in the first five years and every two years thereafter.

Conclusion

An early diagnosis, which was made possible in this case by the adequate interpretation of the imaging scans, enables a more rapid and effective intervention and, as a consequence, better patient outcomes and rehabilitation.