CHAPTER 11 NASAL POLYPOSIS NASAL POLYPUS The polypus is a projection of oedematous raucous membrane composed of loose fibro-oedematous tissue, the surface of which is covered with ciliated epithelium. Small blood vessels traverse the surface and are sometimes visible to the naked eye. There is a variable degree of infiltra- tion of round cells, and in allergic polypi large numbers of eosinophils are found. Any condition of hyperaemia or inflammation within the nose or sinuses may give rise to polypus formation. Polypi may be found in cases of sinusitis, allergic conditions or malignancy. Nasal polypi are uncommon in childhood or adolescence but they are common in adult life. Those arising early in adult life are usually of allergic origin. Nasal polypi are more common in males than in females. Nasal polypi occur most frequently in the ethmoidal region and they may be pedunculated or sessile arising almost always from the lateral wall of the nasal cavity. They may be attached to the middle concha, but usually arise from the ethmoidal labyrinth of cells and appear in the nasal cavity through the ostia as protrusions into the middle meatus. They enlarge partly by gravity and partly by nose blowing by virtue of an increase in their fluid content aided by a constriction of the blood vessels in the bony walls of the ostia which results in oedema. Nasal polypi may be single but are usually multiple, and they may be unilateral but are more often bilateral. They vary in size, and may grow as big as a large grape. SYMPTOMS. The principal symptom is nasal obstruction. As polypi are slow growing there may be a considerable collection before the patient becomes aware of the obstruction. At times the patient suddenly becomes conscious of a blockage after a cold when congestion and nose blowing cause a rapid increase in size. Patients vary greatly hi their tolerance of nasal obstruction, some complaining bitterly of the blockage of a single polypus while others endure large multiple polypi for months before seeking advice. Occasionally a pedunculated polypus in the posterior part of the nasal cavity may swing forwards on expiration to act as a ball-valve and cause blockage. The pressure of large oedematous masses of polypi may distend the nasal cavities to cause a visible broadening of the external nose (fig. 24). On occasions, usually during a cold, a polypus may so enlarge as to appear at the anterior naris and be seen by the patient. There may be a complaint of frontal headache, and there is often a loss of the senses of smell and taste. Nasal catarrh is often present, either thin and watery in the case of allergic polypi or mucopurulent if there is an underlying chronic infection.