Osseous metaplasia in a nasal polyp: report of a rare case and review of the literature.

Metaplasia is the conversion of one adult tissue or cell type into another tissue or cell type. Although osseous metaplasia has been described in many parts of the body, it is rarely encountered in the head and neck region, especially in nasal polyps. This article reports a case of unilateral sinonasal polyp containing areas of osseous metaplasia in a 44-year-old woman presenting with nasal obstruction. Also included are a brief discussion of osseous metaplasia in the head and neck region and a literature review.