What is a nasopharyngeal polyp?
Inflammatory polyps that develop at the level of the nasopharynx and the middle ear are non-neoplastic masses which are thought to originate in the epithelial layer of the timpanic bulla or the Eustachian tube. Polyps can also emerge from the epithelium lining the external ear canal in association with otitis.
The etiology of nasopharyngeal polyps is not very clear and congenital pathologies as well as underlining inflammatory diseaseses such as bacterial or viral infections and cronical inflammations are discussed.
Most affected are the cats younger than 3 years of age, but some studies found the average age of the patients to be arround 6-7 years and up to 17,5 years in some cases. The studies citing such advnaced ages implied that polyps developed at a younger age, but remained undiagnosed for a long period.
How to diagnose a nasopharyngeal polyp?
The diagnosis is made based on patient history and clinical examination and confirmed through diagnostic imaging, endoscopy and histopathology.
The clasical clinical signs associated with nasopharyngeal polyps include sneezing andheavy breathing. When a nasopharyngeal polyp reaches a large size (and is located in the nasopharynx) or there are bilateral polyps (extending into the nasal cavities) they cause reduction of the upper airways and are associated with loud breathing noises, nasal discharge, snorring and even vestibular disorders (head tilt, balance disorders). Sometimes nasopharyngeal polyps can be associated with Horner syndrome. Large polyps can lead to difficulties in the act of swallowing and anorexia. Direct or indirect examination (endoscopy and sample retrieval) can be of great help to the clinician in diagnosing this type of pathology (depending on the size and localisation of the polyp). Radiograps (RX), Computed Tomography (CT) and Magnetic Resonance Imaging (MRI) are very good diagnostic tools , providing information about the localisation and size of the polyp and have also a high specificity. Diagnostic imaging can also help differentiate between nasopharyngeal polyps and other pathologies that sometimes similar clinical appearance, such as obstructed or stenotic airways, foreign bodies, neoplasia, thickening or osteolysis of the bullae due to infection. Another advantage when using diagnostic imaging is the ability to assess the regional lymphnodes in order to give a more precise prognosis.