SINONASAL TERATOCARCINOSARCOMA: CASE REPORT AND REVIEW OF LITERATURE

Sinonasal teratocarcinosarcoma (SNTCS) is an extremely rare and highly aggressive malignant neoplasm characterized by a combination of epithelial, mesenchymal, and neuroepithelial components. Fewer than 100 cases have been reported in the literature. We report a case of a 60-year-old male presenting with progressive nasal obstruction and weight loss. Imaging revealed a large infiltrative mass involving both nasal cavities and maxillary sinuses. Initial histopathological diagnosis suggested sinonasal hemangiopericytoma; however, detailed microscopic evaluation and immunohistochemical analysis demonstrated a triphasic tumor composed of glandular epithelial structures, spindle cell mesenchymal elements, and primitive neuroepithelial components forming nests and rosettes. Immunohistochemistry showed positivity for CD56, NSE, and synaptophysin in neuroepithelial areas, Pan-cytokeratin in epithelial components, and H-caldesmon in spindle cells, with a high proliferative index (Ki-67 ~70%). The overall morphologic and immunophenotypic findings supported the diagnosis of sinonasal teratocarcinosarcoma. This case highlights the diagnostic challenge posed by tumor heterogeneity and emphasizes the importance of adequate sampling and comprehensive immunohistochemical evaluation to avoid misdiagnosis on small biopsies.