• Focal accumulations of EDEMA fluid in the NASAL MUCOSA accompanied by HYPERPLASIA of the associated submucosal connective tissue. Polyps may be NEOPLASMS, foci of INFLAMMATION, degenerative lesions, or malformations.
  NLM Medical Subject Headings
  U.S. National Library of Medicine, 2025
• (nasal polyposis) Polypoidal masses arising mainly from the mucous membranes of the nose and paranasal sinuses. They are freely movable and nontender overgrowths of the mucosa that frequently accompany allergic rhinitis.
  Human Phenotype Ontology (HPO)
  The Human Phenotype Ontology Project, 2025
• (nasal cavity polyp) A soft and painless polypoid mass that arises from the mucosa in the nasal cavity. It is usually the result of an inflammatory process. It may recur following surgical resection.
  NCI
  U.S. National Cancer Institute, 2021
• Nasal polyps are fleshy outgrowths of the nasal mucosa that form at the site of dependent edema in the lamina propria of the mucous membrane, usually around the ostia of the maxillary sinuses.
  Merck Manuals
  Merck & Co., Inc., 2025
• Broadly defined, nasal polyps are abnormal lesions that originate from any portion of the nasal mucosa or paranasal sinuses. Polyps are an end result of varying disease processes in the nasal cavities.
  Medscape
  WebMD, 2025
• Nasal polyps are soft, painless, noncancerous growths on the lining of your nasal passages or sinuses. They hang down like teardrops or grapes. They result from chronic inflammation and are associated with asthma, recurring infection, allergies, drug sensitivity or certain immune disorders.
  Mayo Clinic
  Mayo Foundation for Medical Education and Research, 2025
• Nasal polyps (NP) are swellings of the mucosal lining of the paranasal sinuses and are considered to represent a subgroup of chronic rhinosinusitis. They are made up of a mixture of loose connective tissue, edema, inflammatory cells (mostly eosinophils), glandular cells, and capillaries. They are covered with varying types of epithelium,...
  Epocrates
  Athenahealth, Inc., 2019
• Nasal polyp, lump of tissue that protrudes into the nasal cavity and sometimes obstructs it. Polyps can form as the result of allergic conditions or of inflammation and infection. Allergic polyps are usually bright red because of their extensive network of blood vessels. These polyps are most...
  Encyclopedia Britannica
  Encyclopedia Britannica, Inc., 2025