@article {Orgain:2017::e173,
title = "Long-term follow-up of a patient with malignant transformation of inverted papilloma into sinonasal undifferentiated carcinoma",
journal = "",
parent_itemid = "",
publishercode ="",
year = "2017",
volume = "8",
number = "3",
publication date ="2017-10-01T00:00:00",
pages = "e173-e177",
itemtype = "ARTICLE",
url = "https://www.ingentaconnect.com/content/ocean/rhino/2017/00000008/00000003/art00009",
doi = "doi:10.2500/ar.2017.8.0209",
keyword = "endoscopic sinus surgery, long term follow up, radiation therapy, sinonasal undifferentiated carcinoma, Chemotherapy, inverted papilloma, malignant transformation",
author = "Orgain, Carolyn A. and Shibuya, Terry Y. and Thompson, Lester D. and Keschner, David B. and Garg, Rohit and Lee, Jivianne T.",
abstract = "
Introduction:
Inverted papillomas (IP) are benign sinonasal neoplasms, which account for 0.54% of all nasal tumors. IPs have been known to transform into squamous cell carcinoma in 515% of cases. Rarely, transformations to other malignancies have been reported.
Here we report a unique case of malignant transformation of an IP into sinonasal undifferentiated carcinoma (SNUC). 
Methods:
A case report with a literature review; institutional review board exempted. The clinical presentation, radiographic features, surgical intervention,
histopathologic analysis, treatment, and outcome of the case were examined. 
Results:
A 62-year-old man presented with a 3-month history of nasal airway obstruction, rhinorrhea, and postnasal drip refractory to medical therapy. He had a long history of exposure to fumes,
chemicals, dusts, and solvents as a professional painter as well as a 45 pack-year history of smoking and alcohol abuse. The patient was ultimately found to have a left ethmoidal IP with a focus of malignant transformation into SNUC. Endoscopic resection was performed, followed by concurrent
chemoradiation and adjuvant chemotherapy. After surgery, he had no evidence of recurrent disease after 9 years of follow-up. 
Conclusions:
IP is known to transform into squamous cell carcinoma. Here we report a rare case of malignant transformation into SNUC, a much more
uncommon and aggressive lesion. Although traditionally associated with a poorer prognosis, the positive outcome for SNUC observed in this patient may potentially be attributed to early detection and timely therapeutic intervention.",
}