Dr. T. Balasubramanian
Synonyms: Antrochoanal polyp, Killian's polyp, Nasal
History: In 1753 Palfyn first described an
antrochoanal polyp in a female patient. The polyp was found
filling the nasopharynx extending up to the uvula of the
patient. Palfyn believed that this polyp arose from the
choana. It was Killian in 1906 who demonstrated that this
polyp arose from the maxillary sinus antrum.
Definition: Antrochoanal polyp is a benign solitary
polypoidal lesion arising from the maxillary sinus antrum causing
opacification and enlargement of antrum radiologically without any
evidence of bone destruction. It eixts the antrum through the
accessory ostium reaches the nasal cavity, expands posteriorly
to exit through the choana into the post nasal space.
Incidence: It commonly affects children and young
Etiopathogenesis: This disease is
commonly seen only in non atopic persons. Its etiology is
still unknown. Infact this disorder is not associated with
Proetz theory: Proetz
suggested that this disease could be due to faulty development
of the maxillary sinus ostium, since it was always been found
to be large in these patients. Hypertrophic mucosa of
maxillary antrum sprouts out through this enlarged maxillary sinus
ostium to get into the nasal cavity. The growth of the polyp
is due to impediment to the venous return from the polyp. This
impediment occur at the level of the maxillary sinus ostium.
This venous stasis increases the oedema of the polypoid mucosa
thereby increasing its size.
drop next to a constriction causes a suction effect pulling
the sinus mucosa into the nose.
Jakson postulated that changes in mucopolysaccharides of the ground
substance could cause nasal polyp.
Recurrent nasal infections have also been postulated as the cause
for nasal polyp
Vasomotor imbalance theory: This theory
attributes polyp formation due to autonomic
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. The accessory sinus ostium widens progressively,
ultimately at one stage merging with the natural ostium of the
maxillary sinus forming one huge opening into the maxillary
showing the choanal component of antrochoanal
Possible reasons for migration of antrochoanal
polyp in to the post nasal space:
1. The accessory
ostium through which the polyp gets out of the
maxillary antrum is present posteriorly.
The inspiratory air current is more powerful than the expiratory air
current thereby pushes the polyp posteriorly.
natural slope of the nasal cavity is directed posteriorly,
hence the polyp always slips posteriorly.
4. The cilia of the
ciliated columnar epithelial cells lining the nasal cavity always
beats anteroposteriorly pushing the polyp
Histology: Shows respiratory epithelium
over normal basement membrane. The interstitial layer is
grossly oedematous, with no eosinophils. The interstial
layer contains other inflammatory cells.
features: Since the disorder is unilateral (commonly) the
patient always present with
1. Unilateral nasal
2. Unilateral nasal discharge
3. Headache (mostly
5. Sleep apnoea
clausa due to presence of polyp in the post nasal space
Difficulty in swallowing if the polyp extends into the
This picture shows
antrochoanal polyp coming out of the maxillary antrum via the
Anterior rhinoscopy may show the polyp
as glistening polypoidal structures. They will
be insensitive to touch. this feature helps to differentiate it
from a hypertrophied nasal turbinate.
examination will show the polyp if extending posteriorly at
the level of choana. If it fills up the nasopharynx it
will be visible there.
Xray paranasal sinuses will show a
hazy mazillary antrum.
CT scan of paranasal sinuses is
diagnostic. It will show the polyp filling the maxillary
antrum and exiting out through the accessory ostium into the
coronal section showing antral polyp extending out of the antrum via
the accessory ostium
The antrochoanal polyp is dumb bell
shaped with three components i.e. antral, nasal and
This is a surgical
problem. Formerly it was treated by avulsion of the polyp
transnasally. This method led to recurrences. A caldwel
luc approach was preferred in patients with recurrences. In
caldwel luc procedure in addition to the polypectomy, the maxillary
antrum is entered via the canine fossa and the antral component is
Endoscopic approach: With the
advent of nasal endoscope this approach is the preferred one.
Using an endoscope it is always easy to completely remove the
polypoid tissue. The uncinate process must also be completely
excised. Endoscopic approach has the advantage of a complete
surgical excision with negligible recurrance
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