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Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_4416_Библиотеки_им_академика_М_И_Перельмана
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163Chapter 12 Benign Tumors of the Nose and Paranasal Sinuses: Imaging
A
C
B
Figs. 12.2A to C: Recurrent inverted papilloma (post open surgical reduction). (A)
NCCT: Soft tissue density mass along lateral
nasal wall with erosion of cribriform plate
and lamina papyracea (arrowheads) (B) Post
gadT1WI: Cerebriform pattern of enhancement(whitearrow).Intracranialextensioninthe
formofduralenh ancementrightbasifrontallobe
(black arrow). Gliotic changes also seen. (C)
T2WI: T2 intermediate signal intensity mass
withconvolutedappearance(whitearrow).
■ is form of papilloma has no malignant potential.
■ Imaging ndings are nonspecic of an expansile nasal mass.
Oncocytic Papilloma
■ Rare form that occurs in middle aged men.
■ It arises from the lateral nasal wall, and similar to IP has malignant
potential.
■ Imaging ndings are of a polypoidal lesions similar to the other two
forms.
Salivary Gland Type Adenomas
Pleomorphic Adenoma
■ Benign salivary gland tumor, rarely seen in the nasal cavity.
■ Well-dened soft tissue mass (Figs. 12.3A to C).
■ CT: Punctate calcication, if seen is characteristic.
■ MRI: T2 weighted images: Hyperintense with hypointense capsule. Heterogeneous contrast enhancement, free diusion.
1
Section 3 Tumor and Tumor-like Conditions164
A
C
B
Figs. 12.3A to C: Pleomorphic adenoma. (A)
NCCT.Well-denedsofttissuedensitymassin
leftinferiormeatus(arrow).(B)Fatsuppressed
T2WI. Multiple, T2 hyperintense masses with
hypoin tense rim; in inferior meatus (asterisks)
and left premaxillary space (arrowhead). (C)
Post gad T1WI. These lesions in the inferior
meatus (asterisks) and left premaxillary space
(arrowhead)areintenselyenhancing.
BORDERLINE/ LOW MALIGNANT
POTENTIAL SOFT TISSUE TUMORS
Inammatory Myobroblastic Tumor
■ Inammatory pseudotumor.
■ Rare in head and neck region, with commonest site here being the orbit.
■ Sinonasal—rare, reported in sphenoid.
5
■ Imaging ndings (Figs. 12.4A and B) mimic a malignant lesion.
■ CT: May appear hyperdense, bone erosion seen.
■ MRI: T1WI isointense to grey matter. T2WI hypointense. Enhancement
homogenous.
Glomangiopericytoma
■ Synonym: Sinonasal-type hemangiopericytoma.
■ Rare tumor with perivascular myxoid phenotype.
■ Clinical presentation: Nasal obstruction, recurrent epistaxis. Is a cause of
oncogenic osteomalacia.
■ CT: Noncalcied soft tissue density mass in nasal fossa or paranasal
sinus with intense homogenous enhancement.
■ MRI: T1WI isointense; T2WI hyperintense. Enhancement is homogenous.
■ Somatostatin receptor expressing tumor on 68Ga DOTANOC PET CT
(Figs. 12.5A to C).
6
A B
Figs. 12.4A and B: Inammatory myobroblastic tumor/inammatory pseudotumor. NCCT.
• Heterogeneous, hyperdense mass in left maxillary and ethmoid sinuses, nasal cavity
andorbit
• Erosionoflateralnasalwall(arrow)andlaminapapyracea(asterisk).
165Chapter 12 Benign Tumors of the Nose and Paranasal Sinuses: Imaging
A
C
B
Figs. 12.5A to C: Glomangiopericytoma.(A)NCCT.
Softtissuemasswithmildexpansionofright posteriorethmoid cell (asterisk). (B) CECT.Enhancing
soft tissue mass (arrow) in right posterior ethmoid
cell. (C)68Ga-DOTANOCPET CT. Somatostatin
receptorexpressingtumor(arrowhead).
■ Biopsy: Characteristic perivascular hyalinization, no or minimal atypia
seen.
BENIGN SOFT TISSUE TUMORS
Hemangioma
■ Benign vascular tumors. Unlike soft tissue hemangioma elsewhere in
the head and neck region, SN hemangiomas are uncommon lesions.
Section 3 Tumor and Tumor-like Conditions166
A
C
Figs. 12.6A to D: Hemangioma sphenoid sinus.(A)CECT(bonewindow).Largeexpansile
lesionsphenoidsinuswithfocalboneerosion(arrow).(B)T1WIand(C)T2WI.Intermediate
signalonT1WI and T2WI (asterisk in BandC). (D) Post gad T1WI. Intensepostcontrast
enhancement(asterisk).
B
D
■ Most of these are in nasal cavity, and less frequently in sinuses.
■ Seen in young patients.
■ Imaging:
• Expansile lesions with bone remodeling/focal erosions. Sclerosis may
also be seen. However, lesions can be aggressive with signicant bone
destruction.
7
• Contrast enhancement can be variable—Intense or scattered nodular
with gradual ll-in, depending on the amount of brosis/hemorrhage
vs the vascular proliferation (Figs. 12.6A to D).
• Calcication may be seen.
• MRI is nonspecic. It appears hyperintense on T2WI and hypointense
on T1WI.
• Intraosseous hemangioma (Figs. 12.7A and B) reveal an expansile
lesion (sun-burst appearance) which is of mixed density but welldened. e nonossied component shows enhancement.
A B
Figs. 12.7A and B: Nasal bone hemangioma.(A)NCCT.Expansilelyticscleroticlesionofright
nasalbonewithsun-burstappearance(asterisk). (B)CECT.Heterogeneouscontrastenhancement(arrow).
• Also see Chapter 20 for imaging features of hemangiomas in the
pediatric age group.
■ Dierential Diagnosis:
• Should be suspected in any young patient presenting with enhancing
nasal cavity mass. However, in the sinuses the dierential is more
wide depending on the location, especially in those forms with more
brous component or more with aggressive behavior.
167Chapter 12 Benign Tumors of the Nose and Paranasal Sinuses: Imaging
■ e benign tumors (Figs. 12.8A to C) include schwannomas (from the
Schwann cells) and neurobroma.
1
Schwannoma
■ Rare SN tumors; arise in relation to trigeminal nerve branches.
■ Soft tissue masses which are often heterogeneous with areas of necrosis.
■ Bone expansion and remodeling is seen, while presence of bone erosion
alerts to possible malignant change.
■ MRI: ese appear hypertense on T2WI.
Neurobromas
■ More well-dened, homogenous lesions which may cause expansion
(Figs. 12.9A to C).
■ Plexiform types seen in patients of neurobromatosis.
For those lesions occuring in the root of nose/ethmoids please see
Chapters 20 and 23.
Section 3 Tumor and Tumor-like Conditions168
A
C
B
Figs. 12.8A to C: Nerve sheath tumor. NCCT.
• Large expansile soft tissue density mass
(asterisk)rightmaxillarysinus,nasalcavity
• Widening of inferior orbital ssure (black
arrow)
• Widening of right foramen rotundum (arrow)
andcanalforvidiannerve(arrowhead).
BENIGN TUMORS OF BONE AND CARTILAGE
Giant Cell Lesions
■ Include giant cell tumors (GCT), Giant cell reparative granuloma
(GCRG), Brown tumors, Aneurysmal bone cyst (ABC).
■ Have hemosiderin content which shows blooming on the gradient
sequences.
■ Parathormone (PTH) levels should be ascertained in giant cell lesions.
Giant Cell Reparative Granuloma
■ Common sites are mandible/maxilla, infrequently seen involving sinonasal cavity.
■ Hypothesis of origin: It is a reactive response to hemorrhage which
occurs within the bone consequent to trauma/chronic inammation.
■ Age: Young adults, females > males.
■ Imaging ndings (Figs. 12.10A to C): Nonspecic.
■ CT Scan:
169Chapter 12 Benign Tumors of the Nose and Paranasal Sinuses: Imaging
A
C
B
Figs. 12.9A to C: Neurobroma. CECT.
• Large expansile soft tissue density mass
(asterisk)left maxillary sinus, nasal cavity
and sphenoid sinus
• Erosionof roofofsphenoid sinus(black
arrow)
• Homogenous mass with mild post con trast
enhancement (arrowhead)
• Wideningofpterygomaxillaryssureand
extension into pterygopalatine fossa and
infratemporalfossa(arrowinBandC).
• Soft tissue masses with bone erosion.
• Cystic/hemorrhagic foci may be seen within. Expansile but can be
aggressive.
• Erosion of nasal septum, ethmoid bones, sphenoid bones and even
cribriform plate/clivus may be seen.
■ MRI:
• Both T1WI, T2WI reveal a heterogeneous signal intensity.
• Contrast enhancement is also heterogeneous.
■ Treatment: Intralesional steroids or calcitonin are used. Occasionally
surgery is required.
Giant Cell Tumor
■ ese are also rare tumors in the sinonasal cavity and are usually benign.
■ GCT can occasionally show aggressive behavior and metastasize.
■ Imaging (Figs. 12.11A and B):
• CT: Appear as multilocular lesions with uid levels.
• MRI: Low signal intensity on all sequences with moderate degree of
post contrast enhancement.
8
Section 3 Tumor and Tumor-like Conditions170
A
C
B
Figs. 12.10A to C: Giant cell reparative
granu loma.(A)CECT.Large, heterogeneously
enhancing, expansile mass left maxilla with
thinning and rarefaction of posterior wall
(arrow)(B)T2WI.Heterogeneous T2signalwith
central linear hyperintensity (arrowhead) (C)
PostgadT1WI.Heterogeneouspostcontrast
enhancement(asterisk).
A B
Figs. 12.11A and B: Giant cell tumor. (A) T1WI and (B) T2WI.
• Blood-uidlevelswithinthelesion(arrowhead)
• Expansile mixed intensity lesion left sphenoid and posterior ethmoid cells (asterisk)
• Masseffectoverleftopticcanalwithbucklingoftheleftopticnerve(arrow)
• Retainedsecretionsintherightsphenoidsinus.
Aneurysmal Bone Cyst (ABC)
■ ABC usually develops secondarily within another tumor. Primary ABC in
sinonasal masses is far less common than secondary ABC.
■ Appear as expansile mixed density/lytic lesions on CT.
A B
Figs. 12.12A and B: Aneurysmal bone cyst. CECT.
• Expansile mixed density lesion left nasal cavity and ethmoid sinuses
• Multipleuid-uidlevels(arrow).
■ As elsewhere, blood-uid levels are characteristic of ABC (Figs. 12.12A
and B).
■ Gradient sequences maybe used to demonstrate hemosiderin content
within the lesion.
Osteoma
■ Common benign SN tumor.
■ Often incidentally detected lesions.
■ However depending on location, may cause obstruction of sinus drainage
pathways resulting in accumulation of secretions.
■ ere are reported cases of large lesions with skull base erosions and
resultant CSF leak.
■ Common sites: Ethmoid or frontal sinuses.
■ CT: Well-dened high density lesions (Figs. 12.13A to C). e density will
depend upon whether the composition of the lesion is predominantly
brous tissue, spongy bone or compact bone, with respectively increasing
density.
■ MRI: Hypo/isointense on T2 weighted sequences.
1
Osteoblastoma
■ Osteoblastoma is rare in the craniofacial region, being more frequent in
the vertebral column and long bones.
■ In the paranasal sinuses, its description in literature is conned to case
reports.
■ It occurs in young patients (<30 years of age), with no sex predilection.
■ Imaging:
• Plain radiographs and CT scan: Expansile masses with mixed appea-
9
rance of dense sclerotic component, and a nonossied component
(brous on histopathology). Causes bone remodeling.
171Chapter 12 Benign Tumors of the Nose and Paranasal Sinuses: Imaging
Section 3 Tumor and Tumor-like Conditions172
A
C
B
Figs. 12.13A to C: Frontoethmoidal osteoma .
NCCT.
• Large, lobulated dense bony mass
(arrow)
• Expansion of right frontal and ethmoid
sinuses
• Obstruction of frontonasal drainage path-
way(asterisksinBandC).
• On MRI, while the sclerotic component is a signal void, the brotic
component can show intermediate signal intensity on T1 and T2WI
with intense enhancement.
■ Dierential Diagnosis: Osteogenesis imperfecta, GCT, osteoid osteoma,
brous dysplasia:
• Fibrous dysplasia: In FD, the sclerotic component is more homo-
genous, while it is more nodular in osteoblastoma.
• On CEMR: FD shows marginal enhancement. Osteoblastoma shows
more uniform enhancement.
■ On HPE, osteoblastoma is similar to an osteoid osteoma with only
dierentiating point being size (1.5 cm cut-o).
BENIGN GERM CELL TUMORS
Mature Teratoma
■ Uncommon benign germ cell tumor of the nasal cavity and paranasal
sinuses.
■ Shows the typical imaging morphology of teratomas elsewhere in the body.
■ Characteristic presence of soft tissue density lesion with internal fat, uid
and calcication.
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