Monarch Disease Ontology identifier MONDO_0004384 (maxillary sinus inverted papilloma) is a benign neoplasm that arises from the ciliated respiratory mucosa that lines the maxillary sinus. It results from the invagination and proliferation of epithelial cells in the underlying stroma. Also known as: inverted papilloma of maxillary sinus, inverted papilloma of the maxillary sinus.