Nasal polyps are noncancerous inflammatory growths found in the nasal passageway and sinuses. Polyps usually grow from the mucous lining of the paranasal sinuses. They are often gray or pearl in color, glistening and small grape-like or finger-like projections. As polyps grow larger, they cause nasal obstruction and blockage of the sinus ostia. Nasal polyps are frequently associated with recurrent sinusitis, asthma and nasal allergies. Chronic sinusitis associated with nasal polyps is often noninfectious and is often called chronic hyperplastic eosinophilic sinusitis.