Abstract
Radiotherapy is commonly used in the curative treatment of head and neck cancers, serving both definitive and adjuvant roles. As oncologic outcomes improve, there is a rising occurrence of second malignancies among long-term survivors of these cancers. Radiation-induced osteosarcoma (RIOS) is an uncommon malignancy that emerges as a late consequence of radiotherapy. It usually develops within the irradiated area with a latency period of 5 to 20 years after treatment completion. However, cases of RIOS manifesting within a much shorter latency period, such as 2 years, are sporadic and highly atypical. This report presents a case of RIOS, highlighting the clinical course, diagnostic challenges, and management strategies of this aggressive secondary malignancy.