Risk Factors of Recurrence and Malignant Transformation of Sinonasal Inverted Papilloma

Table 1

The Cannady classification [11].

	Localization	Recurrence rate
A	Nasal cavity, ethmoid sinus, medial wall of the maxillary sinus	3.0%
B	Other (than medial) walls of maxillary sinus, sphenoid sinus, frontal sinus	19.8%
C	Extrasinus extension	35.3%