MONDO_0020669 (paranasal sinus cancer) is a primary or metastatic malignant neoplasm involving the paranasal sinuses. Also known as: malignant accessory sinus neoplasm, malignant accessory sinus tumor, malignant accessory sinus tumour, malignant neoplasm of accessory sinus, malignant neoplasm of paranasal sinus, malignant neoplasm of the accessory sinus, malignant neoplasm of the paranasal sinus, malignant paranasal sinus neoplasm.