International Journal of Otolaryngology and Head & Neck Surgery, 2013, 2, 156-159 Published Online September 2013 (
A Review of Inverted Papilloma at a Tertiary Centre:
A Six-Year Experience
Chiun Kian Chai1*, Ing Ping Tang2, Narayanan Prepageran1
1Department of Otorhinolaryngology, University of Malaya, Kuala Lumpur, Malaysia
2Department of Otorhinolaryngology, Faculty of Medicine, University Malaysia Sarawak, Kota Samarahan, Malaysia
Email: *
Received December 16, 2012; revised January 12, 2013; accepted January 30, 2013
Copyright © 2013 Chiun Kian Chai et al. This is an open access article distributed under the Creative Commons Attribution License,
which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Objectives: To ev aluate the clinical presentation and treatment outcome of all patients treated for inverted papilloma at
the University Malaya Medical Centre, Malaysia. Methods: A retrospective review of 22 patients with inverted papil-
loma, treated at our centre, from 1st Januar y 2005 to 31st August 2011. The demographic data, clinical features, r adio-
logical findings, surgical procedures, recurrent rate and malignant transformation were assessed. Result: The com-
monest presentation was a unilateral nasal blockage, comprising 77.3% cases. A total of 19 patients had undergone en-
doscopic surgery while three patients had open surgery performed. The mean duration of the follow-up period was 30.5
months. Seven (31.7%) patients were detected of tumour recurrence during the entire course of follow-up. However,
throughout the follow-up period, none had demonstrated malignant transformation. Conclusion: Endoscopic medial
maxillectomy is a well-accepted approach in treating inverted papilloma. Nevertheless, open surgery still plays an im-
portant role in extensive diseases and in cases of malignancy. Unilateral nasal obstruction is the most important symp-
tom. Repeated pre-operative biopsy or perhaps frozen section of intraoperative biopsies is necessary to avoid misdiag-
nosis. Krouse stage II disease showed the highest recurrent rate of 18.2%. Lifelong follow-up and emphasis on adher-
ence is mandatory for early detection of recurrence and malignant transformation.
Keywords: Inverted Papilloma; Medial Maxillectomy; Endoscopic Surgery
1. Introduction
Inverted papilloma is an important differential diagnosis
of unilateral nasal mass. It is a benign tumour which co m-
monly arises from the lateral nasal wall and rarely from
the mucosa of the paranasal sinuses [1]. Many terms ha ve
been used to describe inverted papilloma, such as Schnei-
derian papilloma, transitional cell papilloma, epithelial
papilloma, and squamous papillary epithelioma [2]. His-
topathologically, it is characterized by invagination of
the epithelial growth into the underlying stroma [3].
Inverted papilloma is locally destructive, with a high
tendency to recur and is associated with malignant trans-
formation [4]. Hence aggressive surgical approach is al-
ways advocated. Since the introduction of endoscopic
surgery, the trend of surgical approach has moved away
from the traditional techniques, e.g. lateral rhinotomy,
Denker procedure and Caldwell-Luc approach, to endo-
scopic approach. The role of endoscopic surgery in in-
verted papilloma is now well established and achieves
similar tumour recurrence rate comparing to open tech-
nique [3,5-7]. Nevertheless, open techniqu e still plays its
role in extensive diseases, significant anatomic distortion
due to previous surgery or in cases associated with ma-
lignancy [8,9] .
2. Materials and Methods
This is a retrospective study of all patients with inverted
papilloma treated in our centre from 1st January 2005 to
31st August 2011. The demographic data, clinical fea-
tures, surgical procedures and the outcome of these pa-
tients were collected from the medical record office and
statistically analysed. All the patients underwent rigid na-
soendoscopic examination, nasal mass biopsy and com-
puted tomography before operations. Krouse staging sys-
tem was used to grade the disease (Table 1). Post-opera-
tively, nasoendoscopic examination was carried out in
clinic setting to look for recurrence or residual disease.
The primary goal of this review is to evaluate the clinical
presentation, the management and the outcome of in-
*Corresponding author.
opyright © 2013 SciRes. IJOHNS
C. K. CHAI ET AL. 157
Table 1. Krouse staging.
Class Tumour Extent
I Tumour confined to nasal cavity
II Tumour limited to ethmoid sinus and medial and superior
portion of maxillary sinus
III Tumor involved t he lateral and inferior aspect of maxillary
sinus, or involveme nt of frontal or sphenoid si nus
IV Tumour outside nose and sinuses, and inclu de malignancy
verted papilloma at our cen tre.
3. Results
A total of 22 patients were analysed. These consisted of
16 males (72.7%) and six females (27.3%) with the age
ranging from 32 to 71 years old (mean age of 53.8 years
old). These 22 patients included 10 Chinese (45.5%),
seven Indians (31.8%), four Malays (18.2%) and one for-
eigner (4.5%).
The most frequent symptom encountered was nasal
blockage, which consisted of 21 (95.5%) patients. Out of
these 21 patients, 17 (77 .3%) patients p resented with un i-
lateral nasal blockage while four (18.2%) patients pre-
sented with bilateral nasal blockage. There were eight
(36.4%) patients presented with rhinorrhoea, six (27.3%)
with anosmia, four (18.2%) with ep istaxis and two (9.1%)
with facial pain (Table 2). The duration of symptoms
ranged from one week to 60 months with the mean dura-
tion of 14.6 months before these patients presented to our
otorhinolaryngology department. Among these 22 pa-
tients, five (22.7%) patients had previous nasal polypep-
tomy done 7 months to 30 years prior to their first pres-
entation at our clinic.
All the patients had nasoendoscopy performed in the
clinic setting. Thirteen (59.1%) patients had right-sided
nasal tumour while nine (40.9%) patients had tumour
over the left nasal cavity. Biopsy was taken in all these
patients, and the histopathological examination showed
inverted papilloma in 17 (77.3%) patients and nasal po-
lyp in five (22.7%) patients. In our study, tumour staging
was done not only b ased on the classical computer tomo-
graphy (CT) findings, but also intra-operative findings,
according to the Krouse classification. There were three
(13.6%) patients with Krouse stage I disease, eight (36 . 4 %)
patients with stage II disease, 10 (45.5%) with stage III
disease and one (4.5%) with stage IV disease (Table 3).
The mean waiting time for surgery was 3.1 months
with a range of less than one month to six months. A
total of 19 (86.4%) patients underwent endoscopic me-
dial maxillectomy while three (13.6%) patients had open
surgery. For the open surgery cases, one patient had
Caldwell Luc approach with endoscopic-assisted tumour
excision (Krouse stage III) while two other patients had
Table 2. Clinical presentations of inverted papilloma.
Symptoms No. of Patients (%)
Nasal Blockage 21 (95.5)
Unilateral 17 (77.3)
Bilateral 4 (18.2)
Rhinorrhoea 8 (36.4)
Anosmia 6 (27.3)
Epistaxis 4 (18.2)
Facial Pain 2 (9.1)
Table 3. Number of cases according to Krouse staging with
the site of involvement.
Stage Nose Maxillary
sinus Frontal
sinus Sphenoid &
Base of skullTotal
I 3 0 0 0 3
II 0 8 0 0 8
III 0 8 2 0 10
IV 0 0 0 1 1
lateral rhinotomy with medial maxillectomy (Krouse
stage II). The mean duration of surgery was 102.4 min-
utes for endoscopic surgery, compared to 165 minutes for
open surgery. Post-operatively, two (9.1%) patients from
endoscopic group complained of epiphora and one of
them suffered peri-orbital oedema with transient diplopia.
The eye symptoms resolved spontaneously after few days.
The mean duration of hospital stay was 4.6 days in en-
doscopic group.
The mean duration of the follow-up period was 30.5
months. A total of 11 (50.0%) patients had defaulted fol-
low-up after the mean duration of 15.7 months post-
operatively. Recurrence was detected in seven (31.7%)
patients and two (9.1%) of them had recurrence twice.
These include four (18.2%) patients with Krouse stage II
disease, two (9.0%) with Krouse stage III disease and
one (4.5%) with Krouse stage IV disease (Table 4). All
these patients had undergone endoscopic medial maxil-
lectomy. Maxillary sinus was found to be the commonest
site of recurrence, comprising 44.4% cases (Table 5).
The mean duration of recurrence was 21.4 months with a
range of six to 72 months. All recurrences were treated
with endoscopic tumour excision. Throughout the entire
course follow-up period, none of the patients demon-
strated malignant transformation.
4. Discussion
In our study, the mean age of patients was 53.8 years old,
with male to female ratio of 2.7:1. These were consistent
with most of the other studies conducted [2,4]. The most
common presentation in our study was unilateral nasal
Copyright © 2013 SciRes. IJOHNS
Table 4. Recurrence according to Krouse stage.
No. of Patients (%)
Krouse Stage First Recurrence Second Recurrence
I 0 1
II 4 (18.2) 1 (4.5)
III 2 (9.0) 1 (4.5)
IV 1 (4.5) 0
Table 5. Number of cases according to the site of recur-
No. of Patients
Site of Recurrence First Recurrence Second Recurrence
Nose 2 1
Maxillary sinus
Lateral wall
Anterior wall
Sphenoid 1 1
blockage (77.3%), followed by rhinorrhea (36.4%), an-
osmia (27.3%) and epistaxis (18.2%). In other words, uni-
lateral nasal blockage is the co mmonest symptom, which
demonstrates a similar highest percentage as compared to
64% to 81% described in other literatures [2,8].
Clinically it is difficult to differentiate between in-
verted papilloma and inflammatory polyp since they
share similar symptoms and signs. Nevertheless, detec-
tion of the unilateral nasal mass should raise the index of
suspicion for inverted papilloma [2]. In such circum-
stances, pre-operative biopsy plays an important role in
confirming the diagnosis. In our study, however, five
(22.7%) patients had initial pre-operative biopsies show-
ing inflammatory polyps instead of inverted papilloma.
These patients had functional endoscopic sinus surgery
(FESS) performed, which included uncinectomy, widen-
ing of maxillary antrum, anterior and posterior ethmoi-
dectomy. The diagnosis of inverted papilloma was later
established from the histopathological specimens sent
from these surgeries, proposing the need of endoscopic
medial mexillectomy later for these patients. Therefore,
in cases highly suspicious of inverted pap illoma, perhaps
it is worthwhile to repeat another pre-operative biop sy, or
take biopsies intra-operatively and send for frozen sec-
tion to avoid misdiagnosis.
Nowadays, tumour staging is mostly performed with
the combination of CT and MRI findings based on
Krouse classification. In Malaysia, MRI of paranasal si-
nuses are not routinely performed due to its expensive
cost and lack in facilities. CT, on the other hand, may
manifest some artifacts, increasing its difficulty in dif-
ferentiating tumours from inflamed mucosa, polyps or
retained fluid in the paranasal cavity [6,10]. Hence, our
study modified Krouse classification by integrating intra-
operative findings to the CT findings.
In recent years, the trend of surgery had moved from
open surgery to endoscopic approach [2,11]. This phe-
nomenon was demonstrated in our study as well, with 19
patients underwent endoscopic surgery and three patients
had open surgery performed. Out of the three, two lateral
rhinotomy cases were performed in year 2005, and one
was converted to Caldwell Luc surgery from initial en-
doscopic approach when the tumour involvement at the
anterior maxillary wall was found intra-operatively. In
view of the high recurrent rate of inverted papilloma and
its association with malignancy, aggressive excision is
always advocated [3 ,5]. In our centre, patients diagnosed
with inverted papilloma would be offered for medial
maxillectomy. Surgical margin is ex tended up to lacrimal
bone anteriorly, sparing the nasolacrimal duct; posteri-
orly, up to the posterior maxillary wall; superiorly, till
the base of the skull and; inferiorly, until reaching the
floor of the nose. Inferior turbinate is removed while
middle turbinate is preserved.
The recurrent rate of inverted papilloma in our study
was 31.7% or seven out of 22 patients. This figure was
slightly higher in comparison with 0% to 27% reported in
others literatures [2-4]. According to the recurrent rate
among our patients in correlation with the Krouse staging,
the highest recurrent rate of 18.2% was demonstrated in
Krouse stage II disease, followed by Krouse stage III
disease (9.1%), and Krouse stage IV disease(4.5%). The
second recurrent rate among these recurrent cases, on the
other hand, was slightly lower in our stud y, consisting of
All the recurrent cases in our study occurred in the en-
doscopic surgery group. Among these patients, two had
tumour involvement at frontal sinus, which made endo-
scopic approach technically difficult for tumour clear-
ance, as endoscopic surgery is possible only if the tu-
mour is confined to the frontal recess or the medial part
of frontal sinus.
The advantages of the endoscopic approach is not only
limited to the cosmetic aspect, it had also shortened the
duration of operation as well as hospital stay [7,12]. The
mean operative duration was 102.4 minutes for each en-
doscopic procedure. The period of hospital stay was 4.3
days for endoscopic cases in our study, including the day
before the operation and the day of operation. In other
words, the period of post-operative hospital stay could be
just about two days.
The tumour recurrence happened as early as six
months or as long as 72 months with the mean time of
21.4 months. Unfortunately, 11 (50.0%) patients had de-
faulted follow-up after a mean period of 15.7 months
after surgeries. Thus, the follow-up period is definitely
Copyright © 2013 SciRes. IJOHNS
Copyright © 2013 SciRes. IJOHNS
inadequate to detect tumour recurrence in this context.
Malignancy is another main concern, which makes long-
term follow-up necessary, with the risk of malignant
transformation ranging from 5% to 21% as well as the
mean duration of 52 months to develop carcinoma, re-
ported in many other literatures [3,7,13]. Currently there
are no universal guidelines for follow-up regime after
surgery. Nevertheless, some authors had suggested for
quarterly follow-up in the first two years, six monthly in
the subsequent two years and yearly thereafter [3]. In
other words, long-term follow up is mandatory and ad-
herence to follow-up should always be emphasized to all
patients [10].
5. Conclusion
Endoscopic medial maxillectomy is a well-accepted ap-
proach in treating inverted papilloma. Nevertheless, open
surgery still plays an important role in extensiv e diseases
and in cases of malignancy. Unilateral nasal obstruction
is the most important symptom. Repeated pre-operative
biopsy or perhaps a frozen section of intraoperative biop-
sies is necessary to avoid misdiagnosis. Krouse stage II
disease showed the highest recurrent rate of 18.2%. Life-
long follow-up and emphasis on adherence is mandatory
for early detection of recurrence and malignant transfor-
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