Sinonasal teratocarcinosarcoma: an unusual neoplasm.

Sinonasal teratocarcinosarcoma (SNTCS) is a very unusual and aggressive neoplasm characterized by the combination of malignant teratoma and carcinosarcoma features, of which less than forty cases have been reported in the literature. We report on a 75-year-old man with SNTCS that involved the left ethmoid, maxillary and sphenoidal sinuses. The tumor showed a complex histological pattern with mature and immature glands, benign squamous and malignant poorly differentiated epithelia, as well as neuroblastoma-like tissue and sarcoma component with rhabdomyoblastic differentiation. This peculiar blend of tissue types makes the diagnosis of this entity a difficult challenge, especially in small biopsies or in tumors only partially removed. This tumor must be differentiated from several types of carcinomas, esthesioneuroblastoma, craniopharyngioma, malignant mixed tumor of salivary gland type and germ cell tumors. The present case represents, to our knowledge, the third SNTCS described in the european literature.