Histopathological parameters of recurrence and malignant transformation in sinonasal inverted papilloma

Abstract

Malignancy was related to the presence of bone invasion (p=0.039), the absence of inflammatory polyp (p=0.033), increase in the ratio neoplastic epithelium:stroma (p=0.037), increase in hyperkeratosis (p=0.030), the presence of squamous epithelial hyperplasia (p=0.044), increase in the mitotic index (p=0.029) and a decrease in the number of eosinophils (p=0.037). Multiple recurrences (without malignancy) were related to frontal sinus origin (p=0.042), increase in hyperkeratosis (p=0.041), the presence of squamous epithelial hyperplasia (p=0.044) and increase in the mitotic index (p=0.031). Clinically benign behavior was related to the presence of inflammatory polyp (p=0.010) and the absence of hyperkeratosis (p=0.008).