Blastomatous tumor with teratoid features of nasal cavity: report of a case and review of the literature.

A case of blastomatous tumor with teratoid features is presented. The polypoid mass was observed in the left nasal cavity of a 72-year-old man. Histologically, the lesion was composed of neuroepithelial cells with blastomatous appearance, cystic squamous nests filled with keratin materials, many mucous glands, complex tubular and glandular structures with edematous fibroblastic stroma. Sinonasal neoplasms including teratoid components and immature neuroepithelium are exceedingly rare. We suggest that the term 'immature teratoma' is more suitable than blastoma or blastomatous tumor when there is no carcinomatous or sarcomatous component besides the immature neuroepithelium and teratoid elements.