OBJECTIVE: Inverted papilloma (IP) is the most common benign neoplasm of the nasal cavity with known risk of recurrence. There is no standardized approach to definitive treatment for attachment sites. This systematic review aims to determine whether surgeon choice of technique differs by anatomic attachment site and whether different surgical techniques contribute to reduced rates of recurrence.
METHODS: PubMed and Ovid Medline.
METHODS: A systematic review was conducted for studies reporting on IP. Those that included IP recurrence rates and primary tumor attachment site were reviewed.
RESULTS: Of 122 published studies, 14 met eligibility criteria, representing 585 patients and a recurrence rate of 5.8%. The maxillary sinus (50.9%) was the most common primary attachment site, and the sphenoid sinus was associated with the highest rate of recurrence (10.4%). The most utilized technique included debulking the tumor, removing mucosa over the attachment site, and drilling the underlying bone. The most common Krouse stage represented was T3 (53.3%). No single technique predicted a propensity for recurrence, but certain techniques are favored depending on IP attachment site. Finally, frozen sections to obtain evidence of clear margins intraoperatively significantly reduced rates of recurrence (3.4% vs 7.3%, P = .045).
CONCLUSIONS: Based on the current literature, the most common technique to address site of attachment involves resecting mucosa and drilling the tumor base. Choice of technique appears to differ for various sites of attachment. Use of intraoperative frozen section analysis appears to be associated with decreased recurrence overall.
METHODS: 3.

Sinonasal inverted papillomas (IPs) are rare tumours arising from the nasal epithelial mucosa. Most lesions are benign, but a subset of IPs progress to dysplasia and squamous cell carcinoma. Although the epidemiology and clinical features of IPs are well known, the pathogenesis is still unclear. Given the established role of human papillomaviruses (HPVs) in the formation of other mucosal tumours including cervical and oropharyngeal cancer, some have suggested the virus may play a role in IP development. However, the association between HPV and IPs has not yet been proven, and the variable detection of HPV DNA in IPs has cast uncertainty on whether the virus plays a major role in pathogenesis. In this review, we summarize early clinical reports and synthesize recent studies that may elucidate the association between HPV and IPs. We also discuss the role HPV may have in the progression of benign IP to dysplasia and malignancy, as well as potential pathological mechanisms. We hope that synthesizing the initial and recent studies on this topic will not only lead to a better understanding of research in the role of HPV in IP development, but also help guide and contextualize future studies.

Malignant conversion of sinonasal inverted papilloma (SNIP) occurs in approximately ten percent of cases. These tumors are classically described as locally destructive, but without metastatic potential. Only four cases of malignant conversion with cervical nodal metastases have been described in the English literature. We present the rare case of a 61-year-old Caucasian male with a nasopharyngeal recurrence of malignant SNIP with cervical and retropharyngeal nodal metastases. The patient underwent endoscopic transpterygoid with nasoseptal flap reconstruction, followed by staged bilateral and retropharyngeal node dissection. Histopathology of the specimens demonstrated poorly differentiated invasive nonkeratinizing squamous cell carcinoma with inverted-type features. Three months after surgery, the patient suffered from C1-C2 fractures consistent with osteoradionecrosis and expired. Although the rate of malignant conversion of SNIP is low, this case highlights the need for aggressive, definitive treatment and surveillance.

OBJECTIVE: To evaluate the clinical presentation, treatment outcome and follow-up of all patients managed with sinonasal papillomas (SP), at a tertiary private otorhinolaryngology centre in Caracas (Venezuela).
METHODS: We reviewed 94 patients with SP that were treated at our otolaryngology center, from July 1st 1993 to June 31st 2015. The demographic data, clinical features, radiological findings, anatomical origin, disease extension into the adjacent structures, surgical approaches performed, histopathology outcomes, recurrent risk, malignant transformation rate and coadjuvant therapies were assessed.
RESULTS: Sixty-five patients (69.1%) were male and 29 (30.9%) female with an average age of 44.5 years (range 9-80 years). All patients underwent endoscopic sinus surgery. The most commont histologic subtypes of SP were inverted papilloma (58 patients; 61.7%), fungiform papilloma (35 patients; 37.2%) and oncocytic papilloma (one patient; 1.1%). SP was associated in 2 patients with undifferentiated squamous cell carcinoma. Twelve patients (12.8%) had disease with extension beyond the sinus without associated malignancy. All these patients received adjuvant treatment with advanced techniques of radiotherapy. The mean duration of the follow-up period was 9 years and 2 months. Eighteen patients (19.1%) had recurrent disease during the entire course of follow-up.
CONCLUSIONS: Complete endoscopic surgical removal of SP is the treatment of choice. In less endoscopically accessible tumours, with peripheral extension or incompletely resected, Intensity Modulated Radiotherapy and Volumetric Modulated Arc Therapy may be indicated. Timely post-operative endoscopic follow-up with biopsy of suspected lesions is important for early detection of recurrences and associated malignancy.

Inverted papilloma is a benign epithelial growth in the underlying stroma of the nasal cavity and paranasal sinuses. The pathogenesis of this lesion remains unclear although allergy, chronic sinusitis and viral infections have been suggested as possible causes. The tumor is well known for its invasiveness, tendency to recur and association with malignancy. Recurrence rates of inverted papilloma are unacceptably high, which actually represents residual disease in most cases. In this study, we have presented a case report and reviewed the histological features of sinonasal inverted papilloma.