Dr. AHMED REFAEY FRCR FRCR RADIOLOGIST RADIOLOGIST.

Dr. AHMED REFAEYDr. AHMED REFAEY

FRCRFRCR

RADIOLOGISTRADIOLOGIST

Parotid spaceParotid space

* Paired lateral suprahyoid neck * Paired lateral suprahyoid neck spaces enclosed by superficial spaces enclosed by superficial

layer of deep cervical fascia layer of deep cervical fascia containing parotid glands, lymph containing parotid glands, lymph

nodes & extracranial CN7 nodes & extracranial CN7 branches.branches.

Image galleryImage gallery

Graphic of a skull Graphic of a skull base shows PS base shows PS ((greengreen) surrouded by ) surrouded by superficial layer, deep superficial layer, deep cervical fascia(cervical fascia(yellowyellow lineline) . PS abuts ) . PS abuts stylomastoid foramen stylomastoid foramen ((arrowarrow) , mastoid tip ) , mastoid tip ((open arrowopen arrow) & EAC ) & EAC ((curved arrowcurved arrow).).

Parotid space anatomyParotid space anatomy

Axial graphic shows Axial graphic shows superficial layer of superficial layer of deep cervical fascia deep cervical fascia ( ( yelow lineyelow line ) ) circumscribes PS.circumscribes PS.

CN7 ( CN7 ( arrowarrow ) divides ) divides parotid gland into parotid gland into superficial & deep superficial & deep lobeslobes

Parotid space anatomyParotid space anatomy

Axial graphic depicts Axial graphic depicts a deep parotid lobe a deep parotid lobe mass pushing the mass pushing the parapharyngeal fat parapharyngeal fat from lateral to medial from lateral to medial ((arrow)arrow) & squeezing & squeezing through the through the stylomandibular notch stylomandibular notch ((open arrowsopen arrows) )


Sagittal graphic of PS Sagittal graphic of PS malignancy (malignancy (arrowarrow) ) shows typical perineural shows typical perineural tumor spread retrograde tumor spread retrograde along CN7 .along CN7 .

Tumor follows CN7 Tumor follows CN7 through stylomastoid through stylomastoid foramen (foramen (open arrowopen arrow) & ) & up mastoid segment up mastoid segment ((curved arrowcurved arrow))

Anatomic relationshipsAnatomic relationships

Directly medial to parotid space ( PS ) is Directly medial to parotid space ( PS ) is parapharyngeal space ( PPS ) .parapharyngeal space ( PPS ) .

Anterior to PS is masticator space .Anterior to PS is masticator space .

Internal structuresInternal structuresParotid glandParotid gland

-superficial lobe represent about 2/3 of parotid space.-superficial lobe represent about 2/3 of parotid space.-deep lobe projects into lateral PPS-deep lobe projects into lateral PPS

Facial nerve ( CN7)Facial nerve ( CN7) -surgical plane between superficial and deep lobe.-surgical plane between superficial and deep lobe.

External carotid arteryExternal carotid arteryRetromandibular veinRetromandibular veinLymph nodesLymph nodes

- Around 20 lymph nodes found in each parotid glandAround 20 lymph nodes found in each parotid glandParotid ductParotid duct

-emerges from anterior PS , runs along surface of masseter muscle , -emerges from anterior PS , runs along surface of masseter muscle , arches through buccal space to pierce buccinator muscle at level of arches through buccal space to pierce buccinator muscle at level of upper 2upper 2ndnd molar tooth. molar tooth.Accessory parotid glandsAccessory parotid glands

-project over surface of masseter muscle-project over surface of masseter muscle-present in about 20% of normal anatomic dissections.-present in about 20% of normal anatomic dissections.

Key concepts or questionsKey concepts or questions

In mass lesions of PS area, is the mass intra or In mass lesions of PS area, is the mass intra or extraparotidextraparotid ? ?

-small , intraparotid masses easy to identify.-small , intraparotid masses easy to identify.Large , deep lobe masses more troublesomeLarge , deep lobe masses more troublesome -mass displace PPS medially-mass displace PPS medially -stylomandibular notch is widened.-stylomandibular notch is widened.

What is mass relationship to facial nerve?What is mass relationship to facial nerve?

-designate mass as superficial , deep or in same plane as -designate mass as superficial , deep or in same plane as intraparotid facial nerve.intraparotid facial nerve.

-superficial lobe mass removed by superficial parotidectomy while -superficial lobe mass removed by superficial parotidectomy while

deep lobe mass requires total parotidectomy.deep lobe mass requires total parotidectomy.

..If malignancy in PS known or suspectedIf malignancy in PS known or suspected ? ?-T1+C MR should be done to evaluate entire CN7 to -T1+C MR should be done to evaluate entire CN7 to

root exit zone of CPA , to role if there is evidence of root exit zone of CPA , to role if there is evidence of perineural CN7 extension.perineural CN7 extension.

Is the PS lesion single or multiple? Unilateral Is the PS lesion single or multiple? Unilateral or bilateral ?or bilateral ?

-multiple bilateral lesions suggest unique DD-multiple bilateral lesions suggest unique DD -Sjogren’s syndrome-Sjogren’s syndrome -BLL-HIV-BLL-HIV -Warthon tumor-Warthon tumor -NHl-NHl -systemic metastasis-systemic metastasis

..

Low garde 1ry parotid malignancy may be Low garde 1ry parotid malignancy may be well circumscribed , hence the surgical well circumscribed , hence the surgical rule rule (( (( all parotid masses must comeall parotid masses must come outout)).)).

Facial nerve plane in parotid can only be Facial nerve plane in parotid can only be estimated not seen with imaging.estimated not seen with imaging.

Parotid LNs are first order drainage for Parotid LNs are first order drainage for malignancies of adjacent scalp & EAC .malignancies of adjacent scalp & EAC .

DD of parotid lesionsDD of parotid lesions

CongenitalCongenital

InflammatoryInflammatory

NeoplasmNeoplasm

* benign* benign

* malignant* malignant

- 1ry- 1ry

- 2ry- 2ry

Differential diagnosisDifferential diagnosisCongenitalCongenital

*1*1stst brancheal cleft cyst brancheal cleft cyst *infantile hemangioma*infantile hemangioma *lymphangioma*lymphangioma• InflammatoryInflammatory *parotiditis*parotiditis *reactive adenopathy*reactive adenopathy *BLL-HIV*BLL-HIV *Sjogren syndrome*Sjogren syndrome *sarcoidosis*sarcoidosis *Kimura disease*Kimura disease• Benign tumorBenign tumor*benign mixed tumor*benign mixed tumor*warthin tumor*warthin tumor*oncocytoma*oncocytoma*facial nerve schwannoma*facial nerve schwannoma*lipoma*lipoma

Malignant tumor,primaryMalignant tumor,primary*mucoepidermoid carcinoma*mucoepidermoid carcinoma*adenoid cystic carcinoma*adenoid cystic carcinoma*acinic cell carcinoma*acinic cell carcinoma*malignant mixed tumor*malignant mixed tumor*squamous cell carcinoma*squamous cell carcinoma

• Malignant tumor , metastaticMalignant tumor , metastatic

*Non-Hodgkin lymphoma*Non-Hodgkin lymphoma*systemic metastasis*systemic metastasis

11stst brancheal cleft cyst brancheal cleft cyst

Parotiditis, acuteParotiditis, acute

Acute infection of parotid glandAcute infection of parotid gland

# # bacterialbacterial---- acute suppurative parotitis, usually -- acute suppurative parotitis, usually unilateral, more than 50 years & neonatesunilateral, more than 50 years & neonates

# # viralviral – acute viral parotitis , more than 75% – acute viral parotitis , more than 75% bilateral , most common cause is mumps, most bilateral , most common cause is mumps, most less than 15 years , peak age 5-9 years.less than 15 years , peak age 5-9 years.

## calculus induced – parotitiscalculus induced – parotitis 2ry to ductal 2ry to ductal obstruction by stone.obstruction by stone.

CT findingsCT findings

NECTNECT- Bacterial and viral – hyperdense enlarged parotid with ill Bacterial and viral – hyperdense enlarged parotid with ill

defined margins.defined margins.- Calculus-induced – parotid duct calculus usually obvious.Calculus-induced – parotid duct calculus usually obvious.

CECT CECT - Bacterial – enlarged diffusely enhancing parotid with Bacterial – enlarged diffusely enhancing parotid with

inflammatory stranding of overlying soft tissues.inflammatory stranding of overlying soft tissues.- Viral – enlarged parotids with mild enhancement.Viral – enlarged parotids with mild enhancement.- calculus-induced – parotid duct dilated with enhancing - calculus-induced – parotid duct dilated with enhancing

walls.walls.


Axial CECT shows Axial CECT shows diffusely enlarged and diffusely enlarged and increased in density increased in density compared to right compared to right side (side (open arrowopen arrow))


Axial CECT shows Axial CECT shows early changes of early changes of acute parotiditis. Note acute parotiditis. Note subtle asymmetry of subtle asymmetry of parotid density with ill-parotid density with ill-defined contours and defined contours and subcutaneous subcutaneous stranding (stranding (arrowarrow). ). Parotid duct is normal Parotid duct is normal ( ( open arrowopen arrow))


Axial CECT revealed Axial CECT revealed intraparotid abscess intraparotid abscess as irregular area of as irregular area of low density (low density (arrowarrow). ). Note extension of Note extension of inflammation with inflammation with carotid space carotid space involvement and involvement and compressed or compressed or thrombosed jugular thrombosed jugular vein ( vein ( open arrowopen arrow).).


Axial CECT shows Axial CECT shows calculus-induced calculus-induced parotiditis. Note parotiditis. Note proximal ductal proximal ductal calculus (calculus (arrowarrow) with ) with intraglandular ductal intraglandular ductal radicle enlargement radicle enlargement ((open arrowopen arrow). The ). The parotid is enlarged & parotid is enlarged & enhancing without enhancing without abscess.abscess.

Benign lymphoepithelial lesions-Benign lymphoepithelial lesions- HIVHIV( BLL-HIV)( BLL-HIV)

Mixed cystic and solid bilateral intraparotid Mixed cystic and solid bilateral intraparotid lesions found in HIV +ve patients.lesions found in HIV +ve patients.

Best diagnostic clueBest diagnostic clue : multiple cystic and solid : multiple cystic and solid masses enlarging both parotid glands usually masses enlarging both parotid glands usually associated with tonsilar hyperplasia & cervical associated with tonsilar hyperplasia & cervical reactive adenopathy.reactive adenopathy.

Thin rim enhacement of cystic lesions with Thin rim enhacement of cystic lesions with heterogenous enhancement of solid lesions.heterogenous enhancement of solid lesions.

5% of HIV+ve patients develop BLL of parotids.5% of HIV+ve patients develop BLL of parotids.

BLL-HIVBLL-HIV

Axial graphic shows Axial graphic shows classic findings of classic findings of BLL-HIV as bilateral BLL-HIV as bilateral intraparotid cysts intraparotid cysts mixed with bilateral mixed with bilateral solid lymphoid solid lymphoid aggregates (arrows). aggregates (arrows). Note associated Note associated adenoidal adenoidal hypertrophy (open hypertrophy (open arrows)arrows)

BLL-HIVBLL-HIV

Axial CECT at level of Axial CECT at level of soft palate shows soft palate shows benign benign lymphoepithelial lymphoepithelial lesion of HIV as lesion of HIV as hypodense cystic & hypodense cystic & mixed cystic-solid mixed cystic-solid lesions of both parotid lesions of both parotid glands with thin glands with thin peripheral peripheral enhancement.enhancement.


Axial CECT reveals Axial CECT reveals bilateral parotid bilateral parotid enlargement 2ry to enlargement 2ry to lymphoepithelial lymphoepithelial lesions of HIV. Note lesions of HIV. Note both cystic (arrows) both cystic (arrows) and solid (open and solid (open arrows) lesions arrows) lesions bilaterally affecting bilaterally affecting the parotid glands.the parotid glands.


Axial STIR MR shows Axial STIR MR shows bilateral intraparotid bilateral intraparotid hyperintense cystic hyperintense cystic lymphoepithelial lymphoepithelial lesions of HIV. Notice lesions of HIV. Notice both superficial and both superficial and deep lobes are deep lobes are involved. Arrows involved. Arrows marks associated marks associated reactive occiptal reactive occiptal nodes.nodes.


Axial T1 +C MR Axial T1 +C MR shows bilateral cystic shows bilateral cystic and solid intraparotid and solid intraparotid lesions of HIV. lesions of HIV. Palatine (faucial) Palatine (faucial) tonsils (arrows) are tonsils (arrows) are hyperplastic and hyperplastic and associated with associated with reactive lateral reactive lateral retropharyngeal retropharyngeal nodes (open arrows)nodes (open arrows)

Sjogren’s syndromeSjogren’s syndrome

SJS – chronic systemic autoimmune SJS – chronic systemic autoimmune exocrinopathy that causes salivary and exocrinopathy that causes salivary and lacrimal gland tissue destruction.lacrimal gland tissue destruction.

* * 1ry SJS1ry SJS – dry eyes , dry mouth , no – dry eyes , dry mouth , no collagen vascular disease.collagen vascular disease.

* * 2ry SJS2ry SJS – dry eyes , dry mouth , with – dry eyes , dry mouth , with collagen vascular disease, most collagen vascular disease, most commonly rheumatoid arthritis.commonly rheumatoid arthritis.

..

Best diagnostic clueBest diagnostic clue: CT shows bilateral : CT shows bilateral enlarged parotids with multiple cystic and solid enlarged parotids with multiple cystic and solid intraparotid lesions with or without intraglandular intraparotid lesions with or without intraglandular calcification.calcification.Imaging appearenceImaging appearence : :

* * early stageearly stage – parotids may appear normal – parotids may appear normal * * intermediate stageintermediate stage – miliary pattern of small – miliary pattern of small

cysts diffusely throughout both glands.cysts diffusely throughout both glands. * * late stagelate stage – larger cystic and solid masses in – larger cystic and solid masses in

both parotids. both parotids.

Sjogren syndromeSjogren syndrome

Axial CECT reveals Axial CECT reveals classic imaging classic imaging findings of later stage findings of later stage sjogren syndrome sjogren syndrome with bilateral with bilateral enlargement, enlargement, heterogeneity & heterogeneity & increased CT density increased CT density of parotid glands. of parotid glands. Note punctate Note punctate calcifications.calcifications.

Sjogren syndromeSjogren syndrome

Axial Axial STIR MRSTIR MR demonstrates early demonstrates early stage stage MRMR imaging imaging findings of Sjogren findings of Sjogren syndrome as bilateral syndrome as bilateral parotid enlargement parotid enlargement with miliary diffuse with miliary diffuse high signal cystic high signal cystic intraparotid lesions.intraparotid lesions.


Axial Axial T1W MRT1W MR shows shows multiple low signal multiple low signal cystic lesions cystic lesions involving both parotid involving both parotid glands diffusely. This glands diffusely. This “ miliary pattern” of “ miliary pattern” of diffuse involvement is diffuse involvement is seen in early stages seen in early stages of Sjogren syndrome.of Sjogren syndrome.

Benign mixed tumor BMTBenign mixed tumor BMT( ( pleomorphic adenoma )pleomorphic adenoma )

Most common benign parotid space tumor- 80%Most common benign parotid space tumor- 80%Age: most common above 40 y.Age: most common above 40 y.SizeSize– variable, may grow to 6-8 cm when in – variable, may grow to 6-8 cm when in deep lobe.deep lobe.Large , asymptomatic mass arising from deep Large , asymptomatic mass arising from deep lobe of parotid is almost always BMTlobe of parotid is almost always BMT80-90 % of parotid BMT involve superficial lobe.80-90 % of parotid BMT involve superficial lobe.Multicentric BMT rare ( less than 1%) , but Multicentric BMT rare ( less than 1%) , but recurrent BMT typically from incomplete recurrent BMT typically from incomplete resection tends to be multifocal.resection tends to be multifocal.

Best diagnostic clueBest diagnostic clue::

* * small BMTsmall BMT– sharply marginated, intraparotid – sharply marginated, intraparotid ovoid mass with uniform parenchymal ovoid mass with uniform parenchymal enhancement.enhancement. * * large BMTlarge BMT– more than 2 cm , lobulated mass – more than 2 cm , lobulated mass with inhomogenous enhancement representing with inhomogenous enhancement representing foci of necrosis and old hemorrhage.foci of necrosis and old hemorrhage. * * deep lobe BMTdeep lobe BMT– pear- shaped , – pear- shaped , inhomogenous mass pushing parapharyngeal inhomogenous mass pushing parapharyngeal space medially.space medially.

BMTBMT

Axial graphic depicts Axial graphic depicts a small predominently a small predominently superficial lobe BMT. superficial lobe BMT.

BMTBMT

Axial Axial T1W MRT1W MR shows shows small , superficial lobe small , superficial lobe BMT (BMT (arrowarrow). Low ). Low signal compared to signal compared to surrounding parotid is surrounding parotid is typical. Lateral margin typical. Lateral margin of retromandibular of retromandibular vein (vein (open arrowopen arrow) ) marks CN7 plane.marks CN7 plane.


Axial garphic reveals Axial garphic reveals a pear-shaped BMT a pear-shaped BMT of the deep lobe of of the deep lobe of the parotid gland. the parotid gland. Notice that despite Notice that despite the size of this tumor, the size of this tumor, the parapharyngeal the parapharyngeal fat can still be seen fat can still be seen ((arrowarrow) being pushed ) being pushed superomedially.superomedially.


Axial Axial T1+C MRT1+C MR with with fat-saturation shows a fat-saturation shows a large , pear-shaped large , pear-shaped BMT extending from BMT extending from the deep lobe the deep lobe anteromedially. anteromedially. Notice the lesion has Notice the lesion has pushed the right tonsil pushed the right tonsil into the high oral into the high oral cavity (cavity (arrowarrow))


Axial Axial T1+C MRT1+C MR shows shows a left parotid tail a left parotid tail intermediate sized intermediate sized BMT with BMT with inhomogenous inhomogenous enhancement (enhancement (arrowarrow). ). As these lesions As these lesions enlarge , their signal enlarge , their signal tends to become tends to become more inhomogenous more inhomogenous on all on all MRMR sequences. sequences.


Axial Axial CECTCECT shows shows recurrent BMT as recurrent BMT as multiple lesions multiple lesions resulting from resulting from intraoperative spillage intraoperative spillage of tumor cells. A of tumor cells. A larger deep (larger deep (arrowarrow) & ) & 2 smaller superficial 2 smaller superficial ((open arrowopen arrow) ) recuurent BMTs can recuurent BMTs can be seen.be seen.

Warthin tumorWarthin tumor

Benign parotid tumor, sharply marginated ,parotid tail Benign parotid tumor, sharply marginated ,parotid tail mass with stricking parenchymal inhomogeneity.mass with stricking parenchymal inhomogeneity.LocationLocation– most comonly within parotid tail superficial to – most comonly within parotid tail superficial to angle of mandible.angle of mandible.SizeSize– 2-4 cm– 2-4 cmMorphologyMorphology – round to ovoid, well- – round to ovoid, well-circumscribed,encapsulated mass or masses ( 20% ).circumscribed,encapsulated mass or masses ( 20% ).Parenchymal inhomogeneity is characterestic.Parenchymal inhomogeneity is characterestic.Cystic component in 30% with thin, uniform walls & CT Cystic component in 30% with thin, uniform walls & CT density of 10-20 HU , with minimal enhancement of solid density of 10-20 HU , with minimal enhancement of solid component.component.

General featuresGeneral features

22ndnd most common benign parotid tumor. most common benign parotid tumor.

20% multicentric, unilateral or bilateral.20% multicentric, unilateral or bilateral.

Mass is painless, slowly growing.Mass is painless, slowly growing.

90% of patients are smokers.90% of patients are smokers.

Increase incidence with radiation exposureIncrease incidence with radiation exposure

Age– mean age = 60 years.Age– mean age = 60 years.

Image interpretation pearlsImage interpretation pearls

Be sure to carefully examine for multiplicity Be sure to carefully examine for multiplicity and bilaterality.and bilaterality.

Well-circumscribed heterogenous multiple Well-circumscribed heterogenous multiple or bilateral parotid masses in or bilateral parotid masses in asymptomatic patient should be asymptomatic patient should be considered warthin tumor.considered warthin tumor.


Axial graphic depicts Axial graphic depicts bilateral mixed solid-bilateral mixed solid-cystic parotid tail cystic parotid tail Warthin tumor. Larger Warthin tumor. Larger left intraparotid tumor left intraparotid tumor is cut in insert to show is cut in insert to show characteristic characteristic parenchymal cystic parenchymal cystic changes (changes (arrowarrow).).


Axial Axial CECTCECT shows shows mildly enhancing mildly enhancing bilateral parotid tail bilateral parotid tail Warthin tumor. Note Warthin tumor. Note marked hetrogeneity marked hetrogeneity of left parotid lesion of left parotid lesion ((arrowarrow) & solid ) & solid composition of right composition of right parotid lesion (parotid lesion (open open arrowarrow))


Axial Axial CECT CECT shows a shows a warthin tumor within warthin tumor within the tail of the the tail of the superficial lobe of the superficial lobe of the left parotid over the left parotid over the angle of the mandible angle of the mandible with classic marked with classic marked hetrogeneity and hetrogeneity and hetrogenous contrast hetrogenous contrast enhancement.enhancement.


Coronal Coronal T1+C MRT1+C MR reveals a warthin reveals a warthin tumor in the left tumor in the left parotid tail (parotid tail (arrowarrow) . ) . Note the significant Note the significant parenchymal parenchymal hetrogeneity with both hetrogeneity with both low and intermediate low and intermediate signal areas seensignal areas seen


Axial Axial CECTCECT shows a shows a primarily cystic primarily cystic warthin tumor of left warthin tumor of left parotid tail (parotid tail (arrowarrow). ). Note the mural nodule Note the mural nodule within the posterior within the posterior portion of the lesion , portion of the lesion , differentiating it from differentiating it from 11stst branchial cleft cyst branchial cleft cyst


Axial Axial CECT CECT demonstrates a demonstrates a large , homogenously large , homogenously dense, solid Warthin dense, solid Warthin tumor of superficial tumor of superficial lobe of left parotid lobe of left parotid ((arrowarrow). Lesions this ). Lesions this size almost always size almost always show significant show significant parenchymal parenchymal inhomogeneity.inhomogeneity.

Mucoepidermoid carcinomaMucoepidermoid carcinoma

Best diagnostic clue:Best diagnostic clue:--low grade MECalow grade MECa: ovoid, well circumscribed, inhomogenous : ovoid, well circumscribed, inhomogenous

massmass--high grade MECahigh grade MECa : ill-defined, infiltrating mass with associated : ill-defined, infiltrating mass with associated

malignant nodules.malignant nodules.Location Location : superficial lobe more than deep lobe.: superficial lobe more than deep lobe.Malignant adenopathy often presentMalignant adenopathy often present

- 1- 1stst order nodes = jugulodigastric nodes ( level 2 ) order nodes = jugulodigastric nodes ( level 2 ) - intrinsic parotid nodes and parotid tail nodes also involved.- intrinsic parotid nodes and parotid tail nodes also involved.

Imaging recommendationsImaging recommendations:: - deep tissue spread and perineural tumor through CN7 are - deep tissue spread and perineural tumor through CN7 are

better defined by MRI , T1 + C delineate MECa because high better defined by MRI , T1 + C delineate MECa because high signal fat of normal parotid tissue provides natural contrast.signal fat of normal parotid tissue provides natural contrast.

Clinical issuesClinical issues

--ageage : usually 35 – 65 y : usually 35 – 65 y- Low gradeLow grade

painless, mobile , slowly enlargingpainless, mobile , slowly enlarging- High grade High grade

painfull, non-mobile, rapidly enlargingpainfull, non-mobile, rapidly enlarging

Image interpretation pearlsImage interpretation pearls

Low grade MECaLow grade MECa may exactly mimic may exactly mimic pleomorphic adenomapleomorphic adenoma

High grade MECaHigh grade MECa has non specific has non specific invasive mass appearance.invasive mass appearance.

Mucoepidermoid carcinomaMucoepidermoid carcinoma

Axial CECT shows Axial CECT shows well-defined well-defined heterogenous mass in heterogenous mass in the right parotid gland the right parotid gland

MECaMECa

* axial T1W MR shows * axial T1W MR shows invasive parotid invasive parotid MECa (arrow) filling MECa (arrow) filling base of stylomastoid base of stylomastoid foramen (open arrow)foramen (open arrow)


Axial Axial T1W MRT1W MR shows shows low grade MECa as a low grade MECa as a homogenous homogenous intermediate signal intermediate signal mass (mass (arrowarrow) in ) in superficial parotid superficial parotid lobe. Notice how lobe. Notice how sharply circumscribed sharply circumscribed the tumor is relative to the tumor is relative to adjacent parotid glandadjacent parotid gland


Axial Axial T2W MRT2W MR in in same patient shows same patient shows well-defined high well-defined high signal MECa (signal MECa (arrowarrow) ) in superficial lobe left in superficial lobe left parotid. A well parotid. A well circumscribed, high circumscribed, high signal intraparotid signal intraparotid mass is more mass is more suggestive of BMT.suggestive of BMT.


Axial Axial CECTCECT shows a shows a holoparotid invasive holoparotid invasive high grade MECa high grade MECa involving the involving the superficial lobe superficial lobe ((arrowarrow) & deep lobe ) & deep lobe ((open arrowopen arrow). Notice ). Notice single intraparotid single intraparotid lymph node (lymph node (curvedcurved arrowarrow).).


Axial Axial CECTCECT in same in same patient again reveals patient again reveals invasive high grade invasive high grade MECa of parotid with MECa of parotid with associated antegrade associated antegrade perineural tumor on perineural tumor on CN7 (CN7 (arrowarrow) and ) and spinal accessory spinal accessory malignant adenopathy malignant adenopathy ((open arrowopen arrow).).


Axial Axial CECTCECT shows shows high grade MECa in high grade MECa in accessory left parotid accessory left parotid lobe as an invasive lobe as an invasive hetrogenous mass hetrogenous mass ((arrowarrow) anterior to ) anterior to masseter muscle. masseter muscle. Open arrow: opposite Open arrow: opposite normal accessory normal accessory parotid.parotid.


Axial Axial T1W MRT1W MR demonstrates an demonstrates an invasive high grade invasive high grade MECa of the right MECa of the right parotid gland (parotid gland (arrowarrow) ) with antegrade with antegrade perineural tumor on perineural tumor on the facial nerve (the facial nerve (openopen arrowarrow))

Adenoid cystic carcinomaAdenoid cystic carcinoma

Previously called Previously called cylindromacylindromaBest diagnostic clueBest diagnostic clue

- - low grade ACCalow grade ACCa: well-circumscribed, homogenous : well-circumscribed, homogenous enhancing massenhancing mass

- - high gradehigh grade : infiltrative , enhancing mass with poorly : infiltrative , enhancing mass with poorly defined marginsdefined marginsSuperficially located, slow growing neoplasm with Superficially located, slow growing neoplasm with propensity for perineural extensionpropensity for perineural extensionPeak age 50-70y , rare before 20 yPeak age 50-70y , rare before 20 yLook carefully for perineural tumor with any parotid Look carefully for perineural tumor with any parotid neoplasm, but particularly ACCa.neoplasm, but particularly ACCa.Imaging findings often non-specific & similar to other Imaging findings often non-specific & similar to other parotid tumors.parotid tumors.

ACCaACCa

Axial graphic depicts Axial graphic depicts high grade parotid high grade parotid ACCa spreading in ACCa spreading in perineural fashion perineural fashion along proximal CN7 along proximal CN7 ((arrowarrow) & via ) & via auriculotemporal auriculotemporal nerve (nerve (open arrowopen arrow) to ) to V3 (V3 (curved arrowcurved arrow).).

ACCaACCa

Coronal Coronal T1W MRT1W MR shows high deep shows high deep parotid ACCa (parotid ACCa (arrowarrow) ) extending through extending through stylomastoid foramen stylomastoid foramen with replacement of with replacement of foraminal fat pad, foraminal fat pad, along mastoid along mastoid segment of facial segment of facial nerve (nerve (open arrowopen arrow).).


((LeftLeft) axial ) axial T1+C MRT1+C MR demonstrates a high grade demonstrates a high grade ACCa as an ill defined ACCa as an ill defined enhancement in deep parotid enhancement in deep parotid lobe (lobe (arrowarrow) extending ) extending medially to infiltrate masticator medially to infiltrate masticator space (space (open arrowopen arrow).).((rightright) coronal ) coronal T1+C MRT1+C MR shows intracranial extension of shows intracranial extension of parotid ACCa through foramen parotid ACCa through foramen ovale (ovale (arrowarrow) along ) along mandibular nerve. Spread from mandibular nerve. Spread from CN7 to CN5 occurred via the CN7 to CN5 occurred via the auriculotemporal nerve.auriculotemporal nerve.

Metastatic disease, nodal, Metastatic disease, nodal, parotidparotid

Lymphangitic or hematogenous tumor spread to Lymphangitic or hematogenous tumor spread to intraglandulr parotid lymph nodes.intraglandulr parotid lymph nodes.

Best diagnostic clueBest diagnostic clue::

- multiple parotid masses in setting of known - multiple parotid masses in setting of known head & neck malignancy.head & neck malignancy.

- size : 5 mm- 4 cm- size : 5 mm- 4 cm

* * Consider recurrent BMT in the differentialConsider recurrent BMT in the differential diagnosis if there is a history of BMT surgicaldiagnosis if there is a history of BMT surgical removalremoval . .

General featuresGeneral features

Parotid gland has intraglandular lymph nodes ( not Parotid gland has intraglandular lymph nodes ( not submandibular or sublingual glands )submandibular or sublingual glands )Normal parotid : up to 32 intraglandular lymph nodesNormal parotid : up to 32 intraglandular lymph nodesParotid nodes are 1Parotid nodes are 1stst order nodal site for skin of upper order nodal site for skin of upper face , external ear , scalp (75%)face , external ear , scalp (75%)Systemic metastasis to parotid nodes rareSystemic metastasis to parotid nodes rareMetastasis = 4% of all salivary neoplasmMetastasis = 4% of all salivary neoplasmClinical presentation usually – external ear, scalp , upper Clinical presentation usually – external ear, scalp , upper face skin cancer with enlarging parotid masses.face skin cancer with enlarging parotid masses.Age= 7Age= 7thth decade decade

Image iterpretation pearlsImage iterpretation pearls

Multifocal unilateral disease is most Multifocal unilateral disease is most suggestive of 1suggestive of 1stst order nodal disease from order nodal disease from adjacent skin sitesadjacent skin sites

Bilateral nodes suggests systemic disease Bilateral nodes suggests systemic disease or hematogenous metastatic spread.or hematogenous metastatic spread.

Metastatic diseaseMetastatic disease

Axial Axial CECTCECT shows shows two unilateral two unilateral intraparotid intraparotid squamous cell squamous cell carcinoma nodes carcinoma nodes ((arrowsarrows). Primary ). Primary tumor on skin of tumor on skin of ipsilateral forehead ipsilateral forehead had been treated had been treated multiple times in the multiple times in the previous year.previous year.

Metastatic diseaseMetastatic disease

Axial Axial CECTCECT in same in same patient shows cervical patient shows cervical neck metastatic nodal neck metastatic nodal spread (spread (arrowsarrows) in ) in addition to parotid addition to parotid nodal disease.nodal disease.


(left)(left) axial axial CECTCECT reveals left reveals left intraparotid melanoma nodal intraparotid melanoma nodal mets (mets (arrowarrow) from left temporal ) from left temporal fossa skin primary. Note fossa skin primary. Note posterior lateral margin of posterior lateral margin of node shows early extranodal node shows early extranodal spread.spread.((rightright) axial ) axial T1W MRT1W MR shows shows ovoid intermediate to high ovoid intermediate to high signal melanoma metastatic signal melanoma metastatic node (node (arrowarrow). Primary tumor ). Primary tumor located on external ear on left. located on external ear on left. Parotid nodes are 1Parotid nodes are 1stst order order drainage for this primary site.drainage for this primary site.

Non-hodgkin lymphoma, parotidNon-hodgkin lymphoma, parotid

Lymphoma involving intra- and periparotid Lymphoma involving intra- and periparotid lymph nodes as primary site or secondry lymph nodes as primary site or secondry in systemic disease.in systemic disease.

Best diagnostic clueBest diagnostic clue: multiple, well-: multiple, well-circumscribed, homogenously mildly circumscribed, homogenously mildly enhancing intraparotid masses with enhancing intraparotid masses with adjacent lymphadenopathy, unilateral or adjacent lymphadenopathy, unilateral or bilateralbilateral

NHLNHL

Axial Axial CECTCECT reveals reveals multiple right multiple right intraparotid lymph intraparotid lymph nodes (nodes (arrowsarrows) ) involved by NHL. involved by NHL.

Dr. AHMED REFAEY FRCR FRCR RADIOLOGIST RADIOLOGIST.

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Transcript of Dr. AHMED REFAEY FRCR FRCR RADIOLOGIST RADIOLOGIST.