Sinonasal teratocarcinosarcoma: a case report of a 41-year-old female.

Sinonasal teratocarcinosarcoma (SNTCS) represents an exceedingly rare and aggressive malignancy, exhibiting a unique combination of teratomatous and carcinosarcomatous features. Phenotypically, these neoplasms consist of benign neural components alongside various malignant epithelial and mesenchymal elements. Consequently, the clinical presentation and therapeutic strategies for this tumor entity still necessitate further case-based elucidation. A case involving a 41-year-old female diagnosed with SNTCS is delineated herein. The patient had experienced right-sided nasal obstruction and intermittent epistaxis persisting for one month. Clinical examination identified a polypoid mass occupying the right nasal cavity, which was subsequently excised surgically. Histopathologic and immunohistochemical study revealed a heterogeneous admixture comprising adenocarcinoma, chondrosarcoma, primitive neuroendocrine elements, and immature squamous components of teratoma origin, Positive staining for epithelial membrane antigen and pancytokeratin was observed in both tumor and neuroepithelial cells. Vimentin expression was positive. Partial positivity was demonstrated for CD99, synaptophysin, chromogranin A, and S-100 protein. Focal positivity was identified for desmin and glial fibrillary acidic protein. Ki-67 staining was positive in approximately 60% of cells within the visual field, substantiating the diagnosis of SNTCS. Given its high degree of malignancy and local invasiveness, complete surgical resection and extensive tissue sampling remain imperative for an accurate diagnosis. Prompt identification and comprehensive management have been associated with improved prognostic outcome.