Clinical features of nasal and sinonasal inverted papilloma associated with malignancy

For IP patients exhibiting these clinical findings preoperatively, we should suspect complication with malignancy and plan a treatment. Even if postoperative histology does not confirm malignancy, we should ensure careful observation because of metachronous malignant transformation or the possibility to overlook small malignant lesions. Our result suggests that our strategy for malignant IP could be a reasonable option.