Outcomes of Aggressive Surgical Resection of Sinonasal Inverted Papilloma with Removal of Bone at the Attachment Site

Objectives: In current literature, sinonasal inverted papillomas (IP) have a high risk of recurrence (14–21%) and are associated with malignant transformation (9–13%). The mainstay management of IP is complete local resection. Despite this, most recurrences are attributable to inadequate resection at the attachment site. The aim of this study is to present our experiences with aggressive surgical management of IP with wide bone drilling and removal at the tumor attachment site.

Methods: We present 21 consecutive patients with histopathological diagnosis of IP who received surgical management with bone resection from March 5, 2013 to June 24, 2019. Results are based on the experiences of one surgeon at one clinical center. Data collected include staging, extension of tumor, tumor attachment site, surgical approach, complications, and recurrences.

Results: All patients underwent endoscopic sinus surgery with wide resection of bone underlying the tumor attachment site. Twelve patients (57%) were referred to our institution due to recurrence or incomplete resection. Eight patients (38%) required a combined external approach (5 Caldwell-Luc, 2 external brow, 1 bicoronal). Tumor involved the anterior skull base in 6 cases (29%) and orbit in 1 case. Three tumors had multiple attachments. Median follow-up time was 6.5 months (range: 1–36.3). Intraoperative cerebrospinal fluid leak was observed in two cases; one required repeat surgery for repair. Seven patients required medial maxillectomy. One patient had transient epiphora postoperatively. No recurrences were observed in this case series.

Conclusion: Resection of bone at the tumor attachment site seems to contribute toward minimizing the risk of recurrence. Combined endoscopic and external approaches may be required for tumors with attachment sites in the anterior or lateral walls of the maxillary sinus and frontal sinus.

Table 1 Tumor characteristics

Tumor extension	Krouse staging:(cases)	Cannady staging:(cases)	Attachment site	Recurrences
N	T1:(4)	A:(4)	NS-post; SR,NS-post; SR; SR	0
M	T3:(2)	B:(2)	M-ant; M-lat	0
F	T3:(1)	B:(1)	F	0
N+M	T2:(1)T3:(5)	A:(1)B:(5)	M-med; M-ant; M-ant; M-post; M-post; M-lat	0
N+E+M	T3:(2)	B:(2)	M-post; M-lat,ant	0
N+E+S	T3:(2)	B:(2)	S; T-sup, S, NS-post	0
N+E+F	T3:(2)	B:(2)	F; F	0
N+F+EN/ES	T4:(1)	C:(1)	F	0
N+E+M+F+EN/ES	T4:(1)	C:(1)	F	0

Abbreviations: ant, anterior; E, ethmoid sinus; EN/ES, extra-nasal/extra-sinus; F, frontal sinus; inf, inferior; lat, lateral; M, maxillary sinus; med, medial; N, nasal cavity; NS, nasal septum; post, posterior; S, sphenoid sinus; SR, sphenoid rostrum; sup, superior; T, turbinate.