Antrochoanal Polyp

  • Antrochoanal polyp is non-cancerous growth arising from the mucous membrane of the maxillary sinus and reaches the opening of the sinus in the nasal cavity through the opening of maxillary sinus in the middle meatus.
  • Also known as Killian's polyp.
  • Exact etiology is not known.
  1. However sinus infection has been incriminated (in contrast to ethmoidal polyp, which is considered as allergic).
  2. It could also be due to faulty development of the maxillary sinus ostium
  3. "Bernoulli's theorem" explains Nasal polyp.
  • Pressure drop next to a constriction causes a suction effect pulling the sinus mucosa into the nose.
  • It is single and unilateral, i.e. it occurs in one of the maxillary sinus. It arises from maxillary sinus and grows backward in the nose towards the choana and may reach the nasopharynx.
  • Polypoidal tissue from the maxillary antrum exits out through the accessory maxillary sinus ostium according to some workers. This accessory sinus ostium is placed posteriorly, which could be the reason for the polyp to present posteriorly.
  1. Possible reasons for migration of antrochoanal polyp in to the post nasal space:
  2. The accessory ostium through which the polyp gets out of the maxillary antrum is present posteriorly.
  3. The inspiratory air current is more powerful than the expiratory air current thereby pushes the polyp posteriorly.
  4. The natural slope of the nasal cavity is directed posteriorly, hence the polyp always slips posteriorly.
  • The cilia of the ciliated columnar epithelial cells lining the nasal cavity always beats anteroposteriorly pushing the polyp behind.
  • The antrochoanal polyp is dumb bell shaped with three components i.e. antral, nasal and nasopharyngeal.
  • Generally occurs in young age group (children and young adults) and is more common in male.
  • Unilateral Nasal blockage (more on expiration than on inspiration)
  • Obstruction may become bilateral when polyp grows into nasopharynx and starts obstructing opposite choana.
  • Hyponasal voice
  • Mucoid nasal discharge
  • Conductive deafness due to eustachian tube dysfunction
  • On examination, polyp may not be visible on anterior rhinoscopy as it grows posteriorly
  • On posterior rhinoscopy - smooth, greyish white, spherical mass is seen in choana.
  • Antrochoanal polyp does not bleeds on touch and will be insensitive to touch. this feature helps to differentiate it from a hypertrophied nasal turbinate. 
  • Xray showing air column between soft tissue mass and posterior wall of nasopharynx is suggestive of Antrochoanal polyp.
  • CT scan of paranasal sinuses is diagnostic. 
  • Histology: Shows respiratory epithelium over normal basement membrane. The interstitial layer is grossly oedematous, with no eosinophils. The interstial layer contains other inflammatory cells.
  • There is no medical treatment for antrochoanal polyp.
  • The treatment of choice is complete surgical removal of polyp along with removal of lining of maxillary sinus to prevent the recurrence.Topical steroids are not recommended post-surgery for Antrochoanal Polyp .
  • Surgeries for antrochoanal polyp include :
Avulsion of a polyp
  • The stalk of the polyp is grasped and gently moved around to tease out the antral lining.
  • Most of the time, avulsion fails to remove the polyp and antral lining completely.
Intranasal polypectomy
  • It was the treatment of choice for all age groups prior to the advent of endoscopic sinus surgery and is still the treatment of choice in those setups where endoscopic surgery is not practised.
Caldwell Luc operation
  • It is indicated if there is a recurrence and the age of the patient is more than 17 years.
At present,it has been replaced by FESS surgery.
  • Now a days with FESS(Functional Endoscopic Sinus Surgery) is the current treatment of choice.
  • FESS is also the treatment for recurrent antrochoanal polyp.
Exam Question
  • Antrochoanal polyp is unilateral and single.
  • Antrochoanal polyp grows backwards to the choana.
  • Antrochoanal polyp is common in children.
  • Endoscopic sinus surgery is the treatment of choice in Antrochoanal polyp(not Avulsion).
  • Intranasal Polypectomy is the most appropriate management for Antrochoanal polyp in children.
  • Antrochoanal polyp does not bleeds on touch.
  • Antrochoanal polyp arises from Maxillary antrum.
  • Killian term is used for Antrochoanal polyp.
  • Antrochoanal Polyp is not pre-malignant in nature.
  • FESS is treatment for recurrent atrochoanal polyp.
  • FESS is the current treatment of choice for a large antrochoanal polyp in a 10 year old .
  • "Bernoulli's theorem" explains Nasal polyp.
  • Topical steroids are not recommended post-surgery for Antrochoanal Polyp .
  • A patient presents with antrochoanal polyp arising from the medial wall of the maxilla. FESS with polypectomy would be the best management for the patient.
  • Antrochoanal polyp is associated most commonly with middle meatus.
  • Xray showing air column between soft tissue mass and posterior wall of nasopharynx is suggestive of Antrochoanal polyp.

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