This study aims to describe the factors associated with dysplastic changes in sinonasal inverted papilloma (SIP) including somatic EGFR mutation, FoxM1 expression, HPV status, and their association with dysplastic changes. A cross-sectional, analytical study was conducted comprising 34 samples of histologically-confirmed diagnosis of SIP. The samples were further grouped into 2 groups: 20 samples without associated dysplastic changes, and 14 samples with associated dysplastic changes. The numbers of FoxM1 positively-expressed cells, EGFR mutation, and HPV status were compared among two groups using appropriate comparative statistics. There was statistically-significant difference of FoxM1 expression between SIP and SIP with dysplasia (10% vs 100%; p<0.001). EGFR mutation was identified in 6 samples (30.0%) of the SIP and 5 samples (35.7%) of SIP with dysplasia. No difference of EGFR mutant proportion among two groups. HPV DNA was detected in 5 samples (25.0%) of SIP versus 9 samples (64.3%) of SIP with dysplasia. There was significant difference of HPV status among two groups (p=0.022). The high-risk subtypes were found in most HPV positive samples (57.1%), while low-risk subtypes and out panel subtypes were found 14.3% and 21.4%, respectively. FoxM1 was overexpressed in SIP with malignant transformation. FoxM1 along with HPV status is associated with dysplastic changes in the SIP. FoxM1 immunostaining is potential to be a biomarker of malignant transformation in SIP.