C31: Malignant neoplasm of accessory sinuses

Malignant neoplasms of the accessory sinuses are a group of cancers that begin in the auxiliary sinuses, which are hollow spaces in the bones around the nose. Much like other cancers, these begin when the body's normal control mechanisms stop working. Old cells do not die and instead form a mass of tissue called a growth or tumor. Not all tumors are cancerous; cancerous tumors can invade nearby tissues and spread to other parts of the body. Common symptoms include chronic sinus infections that do not respond to treatment, pain or swelling in the face, blocked nasal passages, frequent nosebleeds, and decreased sense of smell. These neoplasms may progress steadily or rapidly, often depending on the type and stage of cancer, and primarily affect the respiratory system. Causes can include exposure to certain chemicals, age, and family history of cancer.