Inverted Papilloma

Inverted Papilloma showing the characteristic endophytic growth of epithelial nest. It is the most common sinonasal papilloma found in the lateral nasal wall/paranasal sinus. It is associated with HPV and has a 5-15% risk of malignant transformation.

Exophytic growth of hyperplastic epithelium nest with smooth outer contour with neutrophils and microabscesses in the epithelium.