Hybrid peripheral nerve sheath tumor of the nasal cavity showing schwannomatous, neurofibromatous, and perineuriomatous areas

Soft tissue hybrid peripheral nerve sheath tumors (PNST), including schwannoma-perineurioma or neurofibroma-perineurioma, have recently been described. However, there are no reports on hybrid PNST arising in the nasopharyngeal area. In this article, we report such a case. A 58-year-old Japanese man presented with nasal obstruction and was found to have bilateral polypoid lesions in the middle meatus of the nose. Subsequently, nasal polypectomy was performed. Histologically, the tumor consisted of three components including schwannoma, neurofibroma, and perineurioma. Immunohistochemically, schwannoma, neurofibroma, and perineurioma components were positive for S-100 protein, CD34, and epithelial membrane antigen, respectively. In conclusion, this is the first case of hybrid PNST reported to occur in the nasopharyngeal area. Pathologists should be aware of the possibility that hybrid PNST may present outside soft tissue.