sinonasal polyposis by dr shaista amir

1. By; Dr Shaista Bashir

2.  Polyps are soft tissue pedunculated masses of
oedematous hyperplastic mucosa lining the
upper respiratory tract…..nasal cavity and
sinuses.
 These are benign mucosal lesions.

3.  Commonest sites in order of frequency are;
1. Ethmoids
2. Maxillary antra
3. sphenoids

4. 1. Allergic rhinitis
2. Asthma
3. Cystic fibrosis(child)
4. Kartagener syndrome
5. Nickel exposure
6. Nonneoplastic hyperplastic hyperplasia of
inflammed mucous membranes.

5. Views;
Waters,caldwell,lateral,submental vertex
Features
Opacification of nasal cavity and sinuses

7. SSCT IS THE MODALITY OF CHOICE
 CT is of value for determining anatomical landmarks and
variants,to identify erosive changes,e xcellent to determin
intraorbital extension of sinonasal disease upto the ventral
2/3rd of the orbit. when disease approaches apex…MRI is
next step to assess spread to the cavernous sinus and
intracranial extension.
 Non enhanced CT is performed…value of NECT is the
following;if u see an opacified sinus with hyperdense
content it is usually a benign disease.hyperdensities are due
to,blood,fungus,inspissated secretions.
 FEATURES
1. Hypodense polypoidal,rounded masses in the nasal cavity
and paranasal sinuses enlarging sinus ostium .

8. 2.Expansion of the sinuse,thining of sinus
walls,nasal and ethmoid septa.
3.Bulging of the lamina papyracea leading to
displacement of the eyeballs and hypertelorism
4.Widening of the infundibulum.
5.On post contrast images show peripheral or
occasionally solid
heterogenous enhancement.
6. Erosive changes at anterior skull base.

10. SSCT

11. SNP

12. THINING OF SEPTAE

13.  Reserved for difficult cases especially where is
doubt about the pathology on SSCT.
 MRI is also useful to assess any intracranial or
orbital involvement.

16.  Benign antral polyp which widens the sinus ostium
and extends into nasal cavity;5% of all nasal polyps.
 Age
 Teenagers and young adults
 Features
1. Antral clouding
2. Ipsilateral nasal mass
3. Smooth mass enlarging the sinus ostium
4. No sinus expansion

18. . A sphenochoanal polyp is a solitary mass of low
attenuation on computed tomographic (CT) scans
that arises from the sphenoid sinus and extends
through the sphenoid ostium, across the
sphenoethmoid recess, and into the choana (the
boundary between the nasal cavity and
nasopharynx). Contiguous axial or coronal
magnetic resonance and CT images help clearly
differentiate the rare sphenochoanal polyp from
the more common antrochoanal polyp. The sinus
of origin is important to identify, as the surgical
approach depends on the target sinus.

20.  Sinusitis(air fluid levels,total
opacification,enhancement
pattern,hyperintense secretion on T1WI,rim
enhancement on post gad)
 Cancer(solid central enhancement).
 Fungal disease(focal or diffuse areas of
increased attenuation on ct,signal voids on
mri,rim enhancement on mri).
 Juvenile angiofibroma(involvement of
pterygopalatine fossa).

21. pns

22. Mucocele is end stage of a chronically
obstructed sinus…………an
obstructed,airless,mucoid filled expanded
sinus.
Location;
Frontal(60%),ethmoid(30%).maxillary(10%),sphen
oid (rare)
CAUSES. The most common causes of mucoceles are chronic
infection, allergic sinonasal disease, trauma and previous surgery.

23.  Soft tissue density mass….having mucoid
attenuation.
 Sinus cavity expansion
 Bone demineralisation+remodelingat late stage
but No bone destruction(DDx from neoplasm)
 Surrounding zone of bone
sclerosis/calcification of edges of mucocele(ch
sinusitis).

24.  Macroscopic calcification in 5%(superimposed
fungal infection)
 Uniform thin rim enhancement.
 Protrusion into orbit displacing medial rectus
muscle laterally.
 Expansion into subarachnoid space…. resulting
in CSF leaking.

25. ct

26. cct

27. cct

28. ethmoid

29. Intracranial extension

30.  Paranasal sinus carcinoma
 Aspergillus infection
 Ch infection
 Inverting papilloma

31.  X-ray ;will show an expansion of the sinus
cavity with loss of the scalloped margin of the
normal sinus.
 Sinus is opaque than normal due to secretions
but may on occasions appear more radiolucent
if bone destruction is marked.
 CT;will show the full extent of expansion and is
usually enough to make the diagnosis.
 MRI;may be used to assess the intracranial
extent.

32.  Clinically more obvious as palpable mass at
medial canthus of
eye,proptosis,epiphora..expansion on lacrimal
sac.
 Majority are found in the anterior ethmoid
cells,expansion of the posterior ethmoid cells
are less common and are associated with
sphenoid mucoceles.

33.  Rare
 Involvement of optic nerve,cavernous sinus and
3rd nerve is common due to proximity to these
structures.
 Imaging plays a key role in diagnosis and its
important that condition be recognized by the
radiologist at an early stage and dealt surgically
before vision is compromised.
 CT and MRI show rounded or partially rounded
expansion of the sphenoid sinus as opposed to the
destruction of bone in situ caused by malignancy.

34.  Signal intensity varies with state of
hydration,protein content,hemorrhage,air
content,calcification,fibrosis.
 Hypointense on T1W1+signal void on T2W1
due to inspissated debris+fungus.
 Hydrated secretions are hypo on T1W1 and
hyperintense on T2W1.
 Peripheral enhancement pattern(DDx
neoplasm).

36.  Fungal disease of the paranasal sinuses is
usually diagnosed when an apparent routine
infection fails to respond to normal antibiotic
treatment.
 Acute invasive fungal sinusitis;is the most
aggressive form of fungal sinusitis.it is seen in
immunocompromised patients and source of
morbidity and mortality.
 Clinical features;are rapid development of
fever,facial pain,nasal congestion and epistaxis.

37.  Extension into orbit,cavernous sinus and
intracranial compartment results in decreased
vision.proptosis and neurological deficits.
 Pathology ;originates in the nasal cavity mostly
in the middle turbinate with subsequent spread
into the paranasal sinuses.a number of fungal
agents are implicated..
1. Aspergillus
2. Rhizopus
3. Mucor
4. Absidia

38.  Ethmoids,maxillary antra are commonly
involved,sphenoid sinus may be occasionally
involved,frontal sinuses are rarely affected.
 Mucosal thickening:hypoattenuating
 Bone destruction:extensive/subtle
 Fat stranding outside of
sinus..intraorbital,pterygopalatine
fossa,masticator space.
 Punctate calcifications….diffuse,nodular or
linear

39. sephnoethmoid

41. cct

43.  MRI
 POST GAD

44.  MRI is the modality of choice to asses soft tissue
extension. The findings within the sinus itself are
variable, and range from mucosal thickening, to
complete opacification of the sinus.
 T1 : intermediate low signal
 T2
 fungal mass is of intermediate to low signal
 often associated with fluid / blood elsewhere in the
paranasal sinuses
 T1 C+ (GAD) : peripheral enhancement only
 Hypointense on all sequences due to paramagnetic
effect of heavy metals …… high fungal mycelial
iron,magnesium,manganese content from amino acid
metabolism…DDx from inspissated
secretions/polypoid disease.
 Low signal on T1 and T2 when there is fibrosis.

45.  Complications include :
 intraorbital extension
 intracranial extension
 leptomeningeal enhancement
 intracranial granulomas
 epidural abscess
 vascular invasion
 cavernous sinus thrombosis or dural venous sinus
thrombosis
 mycotic aneurysm formation
 cerebral infarction or cerebral haemorrhage
 systemic dissemination

46.  Differential diagnoses
 acute sinusitis
 blood clot
 sinonasal carcinoma
 mucocoele