DOI: https://doi.org/10.36347/sjmcr.2026.v14i11.021

Pages: 2492-2496

Background: Osteosarcoma of the sinonasal tract and maxillary sinus is an uncommon malignant bone-forming neoplasm. Because its symptoms may be nonspecific and the maxilla permits early extension into adjacent compartments, cross-sectional imaging is essential for diagnosis, local staging, and surgical planning. [1] Case presentation: A 30-year-old patient presented with a painless right cheek swelling, evolving for two months, with no inflammatory signs. The hemodynamic and respiratory examination was stable, and the initial laboratory assessment was reportedly unremarkable. Contrast-enhanced CT of the facial bones demonstrated a roughly rounded, lobulated, spontaneously isodense mass centered in the right maxillary sinus, containing internal calcifications, and showing heterogeneous enhancement with necrotic areas. The lesion caused extensive osseous destruction and invaded the adjacent cheek soft tissues, anterior and posterolateral walls of the maxillary sinus, medial wall with ipsilateral middle and inferior turbinates, orbital floor, and hard palate/alveolar process. Superiorly, it contacted the lateral orbital wall, lysed the orbital floor, displaced the inferior rectus muscle, and produced grade I right exophthalmos. Posterior extension reached the infratemporal fossa while respecting the intervening fat plane at the temporal muscle. The facial artery remained patent. Surgical excision was performed with a right enucleation, with preservation of the superior rectus muscle. Histopathology established the diagnosis of osteosarcoma. Conclusion: The combination of an aggressive destructive maxillary sinus mass, internal mineralization, heterogeneous enhancement, necrosis, and multi-compartment extension should raise suspicion for sinonasal osteosarcoma. CT provides a comprehensive map of bone destruction, tumor mineralization, orbital involvement, and surgical relationships. [2]