Vol. 101  No. July  2008

Sinonasal Inverted Papilloma with New Bone Formation

Keigo Honda and Tomoyuki Haji
(Kurashiki Central Hospital)

Sinonasal inverted papilloma is a benign but locally aggressive tumor with significant malignant potential. Incomplete resection of the tumor often results in local recurrence. On computed tomography, the tumor usually has soft tissue density. High-density areas within the tumor usually represent intratumoral calcification and intratumoral osteogenesis is extremely rare. To the best of our knowledge, only four cases have been reported so far. We report an additional case of sinonasal inverted papilloma with intratumoral osteogenesis. The patient was a 55-year-old Japanese female who presented with symptoms of acute sinusitis. Intranasal polypoid lesion was diagnosed as an inverted papilloma histopathologically. Computed tomography revealed a high-density area lying across the maxillary osteum. Endoscopic resection of the tumor was performed. Histopathological examination of the surgical specimen revealed metaplastic bone tissue surrounded by the tumor. Further investigations are required to elucidate the pathophysiological mechanisms of osteogenesis in inverted papilloma.

Key words :sinonasal inverted papilloma, osteogenesis, endoscopic resection

第101巻7号 目次   Vol.101 No.7 contents