A benign or malignant neoplasm that affects the paranasal sinuses. Representative examples of benign neoplasms include Schneiderian papilloma and salivary gland-type adenoma. Representative examples of malignant neoplasms include carcinoma and lymphoma. The disease is Monarch Disease Ontology entry MONDO_0005289 (paranasal sinus neoplasm). Also known as: accessory sinus neoplasm, accessory sinus tumor, accessory sinus tumour, neoplasm of accessory sinus, neoplasm of paranasal sinus, neoplasm of the accessory sinus, neoplasm of the paranasal sinus, paranasal sinus neoplasm (disease).