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Benign Neoplasms and Tumor-Like Lesions 125
rior meatus. The concomitant presence of infl ammatory polyps may be misleading and can cause a delay
in establishing a proper diagnosis. Therefore, whenever the clinician is faced with a unilateral polypoid
lesion, multiple biopsies are mandatory.
8.6.3
Treatment Guidelines
Surgery is unanimously considered the treatment of
choice for inverted papilloma. Features repeatedly
emphasized in the literature such as multicentricity,
frequent association with squamous cell carcinoma,
and high incidence of recurrences have prompted
most of the authors to identify medial maxillectomy
(by lateral rhinotomy or midfacial degloving) as
the surgical technique of choice (Myers et al. 1990;
Lawson et al. 1995; Outzen et al. 1996). However,
the introduction in the early 1980s of microendoscopic surgery, along with the subsequent refi nement
of instrumentation and the increasing experience in
endonasal surgery for infl ammatory diseases, have
led to successful results in the treatment of inverted
papilloma even with more conservative techniques
(Brors and Draf 1999; Lund 2000; Wi nt e r et al.
2000). According to Lund (2000), there is no single
right or wrong surgical solution but rather a range
of procedures from which a choice should be made
in any individual case.
In our experience, based on the management of 47
patients (Tomenzoli et al. 2004), a microendoscopic
approach is contraindicated when one of the following situations is present: extensive involvement of the
frontal sinus; massive bone erosion (except for the
medial wall of the maxillary sinus and the anterior
wall of the sphenoid sinus); intradural invasion; intraorbital invasion; abundant scar tissue due to previous surgery; association with squamous cell carcinoma. Different microendoscopic resections may be
adopted in relation to the site of origin and the extent
of the lesion. When inverted papilloma is limited to
the middle meatus, anterior and posterior ethmoid,
and/or spheno-ethmoid recess, a type 1 resection,
including anterior ethmoidectomy with clearance
of the frontal recess, posterior ethmoidectomy, a
large middle antrostomy, sphenoidotomy, partial or
middle turbinectomy (according to tumor extent) is
performed. In such a situation, an “en bloc” resection
is easily obtained, making sure that the dissection is
carried out in the subperiosteal plane.
Whenever the lesion extends from the middle meatus into the maxillary sinus or originates from the
medial wall of the maxillary sinus, a type 2 resection
is performed. In addition to all surgical steps of a type
1 resection, the operation includes a medial maxillectomy with or without section of the nasolacrimal
duct, in relation to the anterior extent of the tumor.
Inverted papillomas that originate from or involve
the posterolateral, anterior and/or inferior wall of the
maxillary sinus are better managed through a type
3 resection, which corresponds to the technique indicated by Brors and Draf (1999) as an “endonasal
Denker operation”.
In patients undergoing a Type 2 or 3 resection, “en
bloc” removal is rarely feasible due to the large extent
of the lesion. Therefore, debulking of the nasal portion of the mass is fi rst performed to subsequently
focus on the most critical areas involved by the lesion,
where dissection is always carried out in the subperiosteal plane. Drilling of the bone underlying the diseased mucosa is then performed to ensure surgical
radicality.
In the era when transnasal resection without microendoscopic assistance was the only available technique, “recurrences” ranged from 40% (Oberman
1964) to 78% (Calcaterra et al. 1980). We concur
with other authors (Hyams 1971; Lund 2000) that
most of these “recurrences” were probably “residual”
lesions, since the exposure offered by a transnasal approach did not guarantee an adequate radicality of
the resection and “recurrent” lesions prevalently occurred at the same site of the primary (Lund 2000).
By using external medial maxillectomy or microendoscopic dissection the occurrence of recurrences
has dropped down to a prevalence ranging from
0% (We is sl er et al. 1986) to 29% (Bielamowicz
et al. 1993), and from 0% (Kamel 1995) to 33%
(Stankiewicz and Girgis 1993), respectively.
Even though most recurrent inverted papillomas
present within 2 years following treatment, late recurrences may also occur. Therefore, it is mandatory
to prospectively follow patients with endoscopic controls every 4 months during the fi rst postoperative
year and subsequently every 6 months for at least
4 years. In contrast to other benign diseases such
as juvenile angiofi broma, which requires radiologic
evaluation for early detection of recurrent submucosal lesions (Nicolai et al. 2003), imaging should
be obtained only in patients with clear endoscopic
evidence of disease or with a complete stenosis of
sinus ostium/a precluding a full endoscopic sinus inspection. In the latter situation, imaging evaluation is
aimed not only at detecting recurrent lesions, but also
to diagnose possible sequelae such as mucocele.
126
8.6.4
Key Information to Be Provided by Imaging
Information on the nature of the lesion
Sites involved by the lesion
Presence and location of bony erosion
Possible association of inverted papilloma with a
malignant neoplasm
8.6.5
Imaging Findings
In general, there are two clinical settings in which
imaging is faced with the diagnosis of inverted papilloma, namely the evaluation of a unilateral nasal
obstruction or the assessment of the local spread
of a lesion already identifi ed by the endoscopic examination (Lehnerdt et al. 2001; Woodruff and
Vrabec 1994).
In the fi rst case, there is a high probability that the
lesion is detected on a screening CT for rhinosinusitis, while in the second one the patient is more frequently imaged by MR.
Almost all inverted papillomas are unilateral.
Bilateral involvement has been reported; it is more
likely related to the perforation of the nasal septum
rather than to an actual multifocal origin (Yousem et
al. 1992; Dammann et al. 1999).
The imaging features typical of inverted papilloma
are based on the site of origin, the pattern of changes
of the lateral nasal wall framework, and – respectively
– the lobulated surface contour on CT and the striated
inner pattern on MR.
Most inverted papillomas arise from both surfaces
of the lateral nasal wall, i.e., the nasal and maxillary.
Those originating from the middle meatus spread
early into the maxillary sinus (Savy et al. 2000) via
remodeling and destruction of its very thin or dehiscent medial bony wall. Those originating from the
maxillary sinus tend to fi ll the cavity and further gain
access into the nasal cavity via the accessory ostium
or via the physiologic ostium.
On CT, high densities within the inverted papilloma are shown in up to 50% of cases; more frequently they appear multiple and discrete. It has been
demonstrated by Som and Lidov (1994) that in most
cases they represent residual bone included within
the lesion rather than calcifi cations (Figs. 8.14, 8.15).
Nevertheless, displacement and remodeling of sinusal
walls may be observed at the same time (Fig. 8.16).
The peculiar macroscopic arrangement of inverted
papilloma is characterized by the alternation of quite
R. Maroldi et al.
Fig. 8.14 At CT, an inverted papilloma arising from left superior turbinate (long arrows) fi lls the superior meatus, and
abuts the ground lamella of the middle turbinate that shows
irregular sclerotic changes (short arrows)
regular parallel folds made of a highly cellular metaplastic epithelium and of an underlying less cellular
stroma. On CT examination, when surrounded by air,
these folds give inverted papilloma its typical lobulated contour, which is consistent with the endoscopic
appearance of a polypoid lesion with several microdigitations on its surface (Dammann et al. 1999). MR
does more, because the inner macroscopic arrangement is demonstrated as a septate striated pattern
or a convoluted cerebriform pattern both on T2 and
contrast-enhanced T1 (Yousem et al. 1992; Ojiri et
al. 2000). Thus, on T2 these parallel folds of inverted
papilloma appear as thick striations of hyperintense
signal alternate with thinner ones, closer to fat intensity. The thinner striations have been correlated with
the metaplastic epithelium, while the thicker ones
have been considered to correspond to the less cellular edematous stroma. On contrast-enhanced T1, the
stroma shows a strong enhancement while the thinner epithelium has a lesser enhancement (Fig. 8.17).
This pattern was described by Yousem et al. (1992)
in 5/10 patients while, recently, Ojiri et al. (2000)
demonstrated the striated appearance in 8/10 patients on both T2 and contrast-enhanced T1.
In our experience of 20 inverted papillomas (their
size ranging from 1 to 6 cm) the pattern was demonstrated in all studies on contrast-enhanced T1,
while on T2 it was detectable only for lesions more
than 3 cm in size (Maroldi et al. 2004). One possible
explanation for the increasing observation of this
fi nding could be the improved spatial resolution. In
fact, Yousem et al. (1992) acquired images with a 256
matrix, Ojiri et al. (2000) obtained slices of 3-mm of
Benign Neoplasms and Tumor-Like Lesions 127
a
Fig. 8.16. At CT, a maxillary sinus inverted pap-
illoma fi lls the whole paranasal cavity and displaces all sinusal walls. Focal remodeling and
thinning of the posterior aspect of medial si-
b
nus wall is seen (arrows), suggesting the extent
through the posterior fontanelle area, a path of
lesser resistance
c
d
Fig. 8.15a–d. Inverted papilloma of left posterior ethmoid
sinus. At CT, the lesion extends into both sphenoid sinuses.
Lobulated contours are well detectable on bone-window images (a,b). Non-homogeneous density and irregular bone den-
sities are more evident on soft-tissue windows (c,d)
thickness. Our protocol entails 512 matrix with a 210mm FOV on axial planes; slices of 2–3 mm of thickness are used, therefore providing a higher resolution
(Maroldi et al. 2004).
The combined use of thin slices and multiple
planes of examination makes it possible to recognize
that the geometry of the lesion (i.e., the orientation
of the septa) depends on the growth along least resistance areas (Fig. 8.18). Moreover, this striated appear-
ance is particularly evident in those narrow spaces
(i.e., ethmoid infundibulum, fontanelle, meatus)
where the lesion is constricted by adjacent structures.
In effect, the cerebriform convoluted pattern can be
resolved by this examination technique in a complex
combination of several parallel or fan-shaped groups
of folds (exiting/entering holes/fi ssures), merging
the concept of striated septa with the one of curvilinear convoluted cerebriform pattern. In addition,
it is sometimes feasible to identify the site of origin
– or the path of growth – by tracing back the quite
parallel septa to their center. Besides showing a high
sensitivity, this pattern proves to be highly predictive of inverted papilloma. In our series it was actually observed only in two malignant tumors: in both
cases pathologic examination of the surgical specimen demonstrated areas consistent with inverted
128
R. Maroldi et al.
Fig. 8.17a–d. Striated inner pattern of
inverted papilloma on MR. Plain (a) and
enhanced (b) axial SE T1, TSE T2 (c) and
enhanced SE T1 (d) on the coronal plane.
The alternation of quite regular parallel folds is detectable on all sequences
(arrows). Displacement and remodeling
of the posterolateral maxillary sinusal
wall is shown (arrowheads)
ba
c d
ab
Fig. 8.18a–c. Inverted papilloma arising from the left middle turbinate, SE T1 enhanced sagittal (a), axial (b), and coronal (c)
planes. a Because the path of least resistance is on the sagittal plane, the striated parallel septations turn into a fan-like pattern
detectable on the sagittal SE T1 enhanced image (arrows). b The lesion extends into the ethmoid infundibulum and protrudes
into the maxillary sinus (short arrow). Posteriorly, it projects through the choana (arrowheads). Uncinate process (long arrow).
c On the coronal plane, the striated appearance results from the parallel orientation of the septa (black arrows). Integrity of left
lamina papyracea/periorbita is shown (white arrows)
c
Benign Neoplasms and Tumor-Like Lesions 129
papilloma where MR showed the pattern (Fig. 8.19)
(Maroldi et al. 2004). Conversely, foci of squamous
cell carcinoma within the inverted papilloma require
the histological examination to be identifi ed (Yousem
et al. 1992).
8.6.5.1
Diff erential Diagnosis
Inverted papilloma arising from the maxillary sinus
has to be distinguished from antrochoanal polyp,
fungus ball, and from malignant neoplasms (Savy
et al. 2000).
The antrochoanal polyp, though exhibiting a similar pathway of extent, is usually diagnosed in adolescents, rather than in adults, and shows a homogeneous
cystic content. Nevertheless, its variant – i.e., the an-
giomatous polyp – may be more diffi cult to differentiate. In fact, a strangled antrochoanal polyp passing
through a constrictive ostium generally shows a more
complex signal pattern. Its constricted mucosal folds
and vessels resemble linear and parallel/fan-shaped
structures exiting the ostium (Fig. 8.20). Moreover,
the intranasal portion of the sinochoanal polyp exhibits bright enhancement, probably due to stasis. If a
mainly cystic intra-sinusal component is present, an
angiomatous polyp is more probable.
On CT, fungus balls may show fi ndings comparable to those of inverted papilloma, namely remodeling and destruction of the medial antral wall and
discrete densities within the lesion. They are easily
differentiated on MR because almost totally hypointense on T2 sequences.
Generally, squamous cell carcinomas – being the
most frequent antral malignant lesion – are characterized by a more extensive destruction of the bony
walls, and do not show the striated pattern on MR.
The differential diagnosis is more complex for
inverted papilloma presenting as a unilateral nasal
mass. Of course, sinonasal polyposis typically involves both nasal cavities; therefore the detection of
a unilateral polypoid lesion in the adult raises the
suspicion of inverted papilloma among other benign
and malignant neoplasms.
a
Fig. 8.19a,b. Enhanced SE T1 on axial (a) and sagittal (b) planes. a Squamous cell carcinoma of the left ethmoid (1) with erosion
of left nasal bone (2), displacement and remodeling of left lamina papyracea/periorbita (3). The posterior part of the lesion
(black arrows), located in the sphenoid sinus, shows more intense enhancement. Thin hypointense and parallel linear densities,
arranged in a roughly septation pattern, can be detected within the tumor (short black arrows). Pathologic examination of the
specimen demonstrated foci of IP in this area. On sagittal plane (b), two different sites of anterior cranial fossa fl oor abnormalities are demonstrated. Anteriorly, extradural intracranial neoplastic invasion (1) is suggested by the presence of enhancing tissue
extending through the bone/periosteum, covered by thickened enhancing dura. A few millimeters posteriorly, the fl uid signal
intensity of a mucocele secondary to the more lobulated component (black arrows) remodels both the planum sphenoidalis (2)
and the roof/posterior wall of the sphenoid sinus (3)
b
130
R. Maroldi et al.
a
Fig. 8.20a,b. Angiomatous polyp of the right maxillary sinus, TSE T2 and enhanced VIBE on the axial plane
8.6.5.2
Pathways of Spread
There are two problems to solve when assessing the
extent of inverted papilloma: to distinguish it from
intrasinusal-retained secretions, and to defi ne its
relationship with both the orbit and the skull base
(Yousem et al. 1992; Savy et al. 2000). MR can ad-
equately answer both issues (Oikawa et al. 2003).
Three relevant aspects regarding inverted papilloma pathways of spread have to be outlined: adjacent bony structures are destroyed by mean of
pressure erosion; extension into adjacent sinusal
cavities occurs through a centrifugal pattern; involvement of skull base is, usually, late, being observed after several failed surgical exccisions. As
most inverted papillomas arise from the lateral
nasal wall or from the maxillary sinus, they grow
centrifugally into the ethmoid labyrinth and later
into the sphenoid or the frontal sinus (Fig. 8.21).
Thinning and bowing of adjacent bony structures
and of the nasal septum is frequent (approximately
80%–90%).
Erosion is common at the level of the lateral nasal
wall or of the turbinates (more than 80%); it is also
seen in nearly 50% of cases at the level of the ethmoid. Extensive erosion of the lamina papyracea or
of the cribriform plate is more often associated with
Fig. 8.21a–c. Inverted papilloma of left frontal sinus, TSE T2
on the axial plane. The lesion has lobulated contours, intermediate signal intensity, clearly distinguished from surrounding retained hyperintense mucus. Focal areas of posterior wall
erosion are demonstrated [ar rows on (a) and (b)]
a coexistent squamous cell carcinoma (Dammann et
al. 1999).
b
a
b
c
Benign Neoplasms and Tumor-Like Lesions 131
a
c
Fig. 8.22a–d. Post-microendoscopic removal of left nasal wall inverted papilloma. Endoscopy (a), TSE
T2 (b), plain (c) and enhanced (d) SE T1 on the axial plane. a Endoscopy shows complete healing of
the nasal fossa and posterior maxillary sinus wall, which is characterized by mild bulging. b On T2 se-
quence, the bulging corresponds to submucosal thickened connective tissue – due to previous surgery
– showing intermediate signal (asterisk). Thickened hyperintense mucosa invests the zygomatic recess
of left maxillary sinus (white arrows). Periosteal thickening of posterolateral antral wall presents with a
double layer pattern (arrowheads). c On the axial plane, obtained a few millimeters cranial, scar tissue
partially fi lls the maxillary sinus. d After GD-DTPA administration minimal enhancement of the scar
tissue is shown. SS, sphenoid sinus; NS, nasal septum
b
d
8.6.6
Follow-Up
At the end of surgical treatment in almost all inverted
papillomas the removal of middle turbinate, medial
maxillary sinus and anterior sphenoid sinus walls
creates a wide cavity easy to access at endoscopy during the follow-up (Dammann et al. 1999; Petit et al.
2000) (Fig. 8.22).
For this reason, imaging is indicated mainly to
defi ne the extent of a recurrent inverted papilloma,
particularly to demonstrate its relationship with the
skull base or the orbit. Of course, recurrences located
deep in the frontal sinus can be detected by imaging
only. The same diagnostic criteria used to identify
the primary inverted papilloma apply to relapsing lesions. Also in this setting, MR provides a sensitivity
superior to CT (Petit et al. 2000).
8.7
Juvenile Angiofi broma
8.7.1
Defi nition, Epidemiology, Pattern of Growth
Juvenile angiofi broma is a lesion composed of vascular and fi brous elements in varying proportion,
which accounts for 0.5% of all head and neck tumors
132
R. Maroldi et al.
and typically occurs in adolescent males. Recent immunohistochemical and electron microscopy studies suggest that the lesion must be considered a
vascular malformation (or hamartoma) instead of
a tumor (Schick et al. 2002). The point of origin is
identifi ed by some authors in the area of the sphenopalatine foramen, while others, based on the results
of CT or MR imaging, indicate that the lesion takes
origin in the pterygopalatine fossa, at the aperture
of the vidian canal. Juvenile angiofi broma has the
peculiar tendency to grow in the submucosal plane
into the nasopharynx, along the vidian canal into
the basisphenoid, and laterally towards the pterygopalatine and infratemporal fossa. Another important feature of juvenile angiofi broma is the early invasion of the cancellous bone of the pterygoid root;
from here, the lesion can extend laterally to involve
the greater wing of the sphenoid bone. Intracranial
extension mainly occurs into the middle cranial
fossa along the maxillary nerve into the parasellar
region and the cavernous sinus; another pattern involves growth through the inferior and the superior
orbital fi ssures. Erosion of the anterior skull base is
seldom observed. It is noteworthy that most of the
lesions with intracranial extension are extradural;
only very rare instances of juvenile angiofi bromas
crossing the dura have been documented in the literature (Danesi et al. 2000).
8.7.2
Clinical and Endoscopic Findings
Nasal obstruction and epistaxis are the typical symptoms of juvenile angiofi broma; their occurrence in a
young male should always arouse the suspicion of
such a disease. Additional symptoms such as diplopia, cheek swelling, and headache can be reported
by patients with advanced lesions extending into the
superior orbital fi ssure, the infratemporal fossa, and
the cranial fossa, respectively. The endoscopic fi nding of a smooth-surfaced, clearly vascularized, expansile lesion growing behind the middle turbinate
is another important element highly suggestive for
juvenile angiofi broma (Fig. 8.23). Since epidemiologic and endoscopic fi ndings are so typical, biopsy
is almost unanimously considered contraindicated,
since it carries a considerable and undue risk of hemorrhage.
8.7.3
Treatment Guidelines
Even though several methods (i.e., embolization,
cryotherapy, hormonal therapy, chemotherapy) have
been proposed for the treatment of juvenile angiofi broma, surgery is commonly considered the main-
Coronal
ba
Fig. 8.23a,b. Juvenile angiofi broma (JA). a Coronal TSE T2 shows a hypointense mass fi lling the left nasal cavity. It projects among
nasal septum (S), middle (arrowheads) and inferior (I) turbinates. Retained fl uid within the obstructed nasal cavity appears as
hyperintense signal surrounding the inferior turbinate. b Endoscopy demonstrates a bluish and vascularized polyp. I, Inferior
turbinate; M, middle turbinate; S nasal septum
Benign Neoplasms and Tumor-Like Lesions 133
stay. Radiotherapy has also been shown to be effective
in isolated institutions; however, the observation of
a few cases of radioinduced tumors, as well as the
possible alterations of maxillary growth, bring the
validity of this treatment into question.
Since many years, transfacial techniques (through
a lateral rhinotomy or a midfacial degloving) and
the infratemporal approach are considered the
best options. More recently, the rapid spread of
endonasal techniques using endoscopes or both a
microscope and endoscopes has prompted many
surgeons to treat even small and intermediate-size
juvenile angiofi bromas with such a conservative approach with apparently satisfactory results. Even
in our experience, juvenile angiofi bromas involving the nasopharynx, the nasal cavities, the sphenoid, the ethmoid, the maxillary sinus, and/or the
pterygomaxillary fossa can be managed successfully
through endoscopic surgery (Nicolai et al. 2003).
Lesions extending into the infratemporal fossa and/
or the cavernous sinus frequently require an external
approach. The head and neck surgeon is therefore
faced with a wide spectrum of surgical techniques
that can be selected in the single patient mainly in
relation to the size and the extent of the lesion. An
informed consent to switch intraoperatively to an
external procedure should always be obtained from
the patient.
8.7.4
Key Information to Be Provided by Imaging
Confi rmation of the suspected nature of the dis-
ease
Extent of the lesion, with specifi c emphasis on
orbit, infratemporal fossa, intracranial (cavernous
sinus, ICA, dura) and intraosseous involvement
Pattern of vascularization (unilateral vs. bilateral;
recruitment of internal carotid artery branches)
8.7.5
Imaging Findings
The diagnosis of juvenile angiofi broma on CT and
MR is based on three features: the site of origin of
the lesion (Lloyd et al. 2000b); its hypervascular ap-
pearance after contrast enhancement (Schick and
Kahle 2000); and its pattern of growth.
First, as juvenile angiofi broma arises close to the
sphenopalatine foramen – either just on its submucosal aspect or from the adjacent pterygopalatine
fossa – it usually presents as a mass expanded medially into the nasal cavity, and eroding the root of the
pterygoid process.
It has been suggested that the actual site of origin should be a recess of the pterygopalatine fossa
behind the sphenopalatine ganglion, at the exit aperture of the vidian canal (Fig. 8.24). The evidence
that up to 96% of the 72 juvenile angiofi bromas in
the series of Lloyd caused enlargement or erosion of
the anterior part of the vidian canal should support
this hypothesis.
Second, as juvenile angiofi broma mainly consists
of a vascular histological component, the administration of contrast agent – either iodinated or paramagnetic – causes a strong and usually quite homogeneous, enhancement on CT or MR T1 sequences
(Fig. 8.25). Moreover, the diagnosis of juvenile angiofi broma on MR is suggested by the presence – on
both T1 and T2 sequences – of several signal voids
within the lesion, indicating major intra-lesion vessels (Fig. 8.26).
As the mass increases in size, enlargement of the
internal maxillary artery can be directly detected by
CT or MR. Cystic changes are rare; those reported
have been correlated to spontaneous or post-chemotherapy tumor regression (Schick and Kahle 2000)
(Fig. 8.27).
Third, bone involvement by juvenile angiofibroma consists either of bone remodeling – for
example the thinning and anterior displacement
of the postero-superior antral wall – and bone erosion, typically at the level of the pterygoid root. In
the latter case, access to the cancellous content of
the sphenoid bone enables the juvenile angiofibroma to extend deeply into the medullary spaces
of the basisphenoid or, even, to replace the diploe
of the greater wing of the sphenoid (Lloyd et al.
1999). Although bone erosion can be more easily
shown by CT, MR is adequate in demonstrating
cortical erosion and cancellous replacement by tumor (Fig. 8.28).
Therefore, the typical juvenile angiofi broma is
diagnosed by CT or MR with almost total certainty,
making pre-operative biopsy unnecessary. Juvenile
angiofi broma arising outside the lateral margins of
the posterior nares is very rare. Approximately 50
cases have been reported in the literature, the maxillary sinus being the commonest atypical site (Schick
and Kahle 2000).
134
R. Maroldi et al.
Fig. 8.24a,b. Juvenile angiofi broma. Plain CT (a), and plain SE T1 (b) in the axial plane (same patient as in Fig. 8.23). Both tech-
niques demonstrate a lesion arising from the medial aspect of the left pterygopalatine fossa in the region of the sphenopalatine
foramen (black arrows). The exit aperture of the pterygoid/vidian canal is markedly enlarged, whereas its posterior portion is
normal (arrowheads). Chronically retained secretions fi ll the sphenoid sinus, being hyperintense on T1 sequence because of the
increased protein concentration. MR shows a small part of the juvenile angiofi broma abutting the sinusal lumen (white arrows).
Reactive sclerosis of the left pterygoid root spongiosa is demonstrated on both techniques
ba
ba
Fig. 8.25a,b. Juvenile angiofi broma: pattern of enhancement. CT before (a) and after (b) contrast administration, coronal
plane. After contrast injection a bright and quite uniform enhancement is observed. Intracranial extent at the cavernous
sinus level appears equally as a hyperdense nodule (arrows). The epicenter of juvenile angiofi broma is located at the sphenopalatine foramen
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