Résumé
<p><b>OBJECTIVE</b>To study the clinical, radiologic and pathologic features, as well as differential diagnosis of teratocarcinosarcoma in nasal cavity and paranasal sinuses.</p><p><b>METHODS</b>Light microscopic examination and immunohistochemical study was performed in 5 cases of sinonasal teratocarcinosarcoma. The clinical, radiologic and pathologic features were analyzed and the literature was reviewed.</p><p><b>RESULTS</b>All 5 patients were males and their age ranged from 34 to 43 years (mean age = 39 years). The clinical presentation was nasal obstruction, epistaxis and headache. Physical examination often revealed a polypoid mass with contact bleeding. Computed tomography showed a homogeneous nasal mass with obturation of sinuses. Cystic changes, calcification or ossification was not observed. Histologically, the tumor showed a heterogeneous admixture of components from the 3 germ cell layers, exhibiting various degrees of maturation. Squamous epithelium, smooth muscle cells, chondro-osseous tissue, intestinal or respiratory type epithelium, "fetal-type" clear cells and immature neuroepithelium were commonly seen. Immunohistochemical study demonstrated that the epithelial component expressed cytokeratin and epithelial membrane antigen, while the mesenchymal component variably expressed vimentin, smooth muscle actin and S-100 protein. On the other hand, the neuroepithelial component expressed neuron-specific enolase, synaptophysin and chromogranin, and the primitive component expressed CD99. The initial biopsy diagnosis included capillary hemangioma, olfactory neuroblastoma, craniopharyngioma and malignant mixed tumor. Follow-up information was available in all patients. Two of which had local recurrence and 1 had cervical lymph node metastasis.</p><p><b>CONCLUSIONS</b>Sinonasal teratocarcinosarcoma is a rare and highly malignant tumor occurring in sinonasal tract. It manifests mainly in adult males and is characterized by a complex admixture of teratomatous and carcinosarcomatous components. "Fetal-type" clear cells, squamous epithelium and immature neuroepithelium represent important histologic characteristics useful in diagnosis.</p>