Types of nasal polyps
The Egyptian hieroglyphics records nasal polyps identified forty centuries ago. The polyps’ recurrence is also well documented, but the polyp frequency may vary from disease to disease. To select an appropriate treatment, thorough understanding of different types of the polyps is required. Although there is no standardized classification of the polyps, two common classifications based on amount of eosinophils are discussed here.
The clinical classification suggested by P. Van Cauwenberge divides nasal polyps into the following three types:
I. Unilateral polyps
The unilateral polyps are of two types: I.A. and I.B. The predominant cells in the I.A. polyps are eosinophils, whereas red blood cells (RBCs), neutrophils and lymphocytes are the principal cells in the I.B. polyps.
II. Bilateral polyps
The bilateral polyps are also further categorized considering the predominant cells. The II.A. polyps feature eosinophils while II.B. polyps contain neutrophils and lymphocytes. While treating the II.A. polyps, a doctor shall take into account allergic fungal sinusitis, allergic rhinitis, Churg-Strauss syndrome and aspirin intolerance. MRI or CT scan of the sinuses, allergy skin tests and other suitable laboratory tests are required. For instance, fungal cultures and surgical debridement may help in case of the polyp associated with allergic fungal sinusitis.
Inflammation may cause the II.B. polyps. The physician shall consider Young’s and cilia dyskinetic syndromes while treating these polyps. A chest x-ray may also require diagnosing Kartagener’s syndrome, which may accompany these polyps.
III. Miscellaneous – additional information
The third category offers more information about polyps. For example, are polyps associated with immunological abnormalities, bone erosion or anatomical reasons? Are polyps recurrent? This category can be used to analyzing other two types of polyps. For example, The “II.A1 recurrent x 3” implies bilateral polyps mainly with eosinophil cells. These polyps, reappeared thrice after the treatment, are attributed to the aspirin intolerance.
Metin Önerci classified the polyps principally into three categories: inflammatory, choanal / isolated and eosinophilic. The isolated polyps may grow from the uncinate, process, ethmoid bulla or other anatomical structures. The polyps originating from the sinus mucosa are named after the sinus involved. For example, polyps developing in the maxillary sinus are referred to as antrochoanal. The polyps in sphenoid sinus are known as sphenochoanal.
The classification also reviews additional criteria and related diseases. There are three additional criteria: allergy, asthma / COPD and acetylsalicylic acid intolerance. Granulomatosis, vasculitis, primary ciliary dykinesia, congential / acquired immune insufficiency and cystic fibrosis are associated with polyps.
