Salivary Gland Tumorsds

8/6/2019 Salivary Gland Tumorsds

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Salivary Gland Tumors

Marka Crittenden M.D. Ph.D.


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Anatomy

Major Glands

Parotid, submandibular and sublingual glands

Minor Glands Hundreds residing in the oral cavity, pharynx and

paranasal sinuses.


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?

Major Salivary Glands

?

?

?

?


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Parotid Gland

Borders

Superior zygomatic arch.

Posterior angle of mandible under earlobe toward the mastoid tip.

Inferior extends to the inferior aspect of the angle of mandibletoward hyoid bone.

Medial borders of the parapharyngeal-base of skull.

Lateral below the skin of the preauricular cheek-upper neck.

Anterior wraps around ascending ramus of mandible

Facial nerve divides the gland into the superficial (80 %) and deeplobe (20%)

Parotid duct (Stensons) is 5 cm long and opens opposite the secondmolar.

Lymphatic drainage periparotid/intraparotid lvl I lvl II- lvl III.

Accessory parotid lobe Present in 20% of patients.


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Submandibular Gland

Borders Lateral proximal half of the mandible.

Posterior anterior to but near the low anterior margin of theparotid gland.

Inferior approaches the level of the hyoid bone.

Majority of gland lies over the external surface of the mylohyoidmuscle.

Lateral to and abuts the lingual and hypoglossal nerve and ismedial to the marginal mandibular and cervical branch of thefacial nerve.

Drains through Whartons duct in anterior floor of themouth

Lymphatic Drainage Lvl I Lvl II- Lvl III


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Sublingual Gland

10% size of parotid gland

Located anterior floor of the mouth

Borders Lateral medial aspect of mandible Inferior mylohyoid muscle

Lingual nerve courses adjacent to sublingualgland

Drain into the floor of the mouth through Rivinusducts

Lymphatic drainage Lvl I- Lvl II- Lvl III


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Epidemiology

Salivary tumors 7% of head and neck tumors

Parotid tumors 10x more common then submandibularand 100x more common then lingual

Parotid 80% benign (pleomorphic adenoma) Submandibular 50% malignant

Sublingual majority (65-88%) are malignant

Equal incidence between sexes

Risk Factors: nutritional deficiency, exposure to ionizingradiation, UV exposure, genetic predisposition, EBV


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Adenoid Cystic

Cribiform pattern differentiated

Cribiform/solid pattern moderately

differentiated Solid Features undifferentiated

Natural history ranges from months to greater

then 20 years. Lymph Node spread


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Adenoid Cystic

Perineural spread common and can track

along the cranial nerves back to the base of

skull

40% develop pulmonary mets but survival of

10-20 years can occur with pulmonary mets so

primary must be managed


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Metastatic Disease involving Parotid

Mechanism

Lymphatic spread most common from skin

Hematogenous spread - lung Direct extension skin or osseous sarcomas


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Staging

T1 2cm and no extraparenchymal extension

T2 > 2cm but not >4cm without

extraparenchymal extension T3 >4cm and or extraparenchymal extension

T4a invades skin, mandible, ear canal and/or

facial nerve T4b invades skull base and or pterygoid plates

and or encases carotid artery


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Parotid Tumors

Clinical presentation

Asymptomatic mass

Cranial nerve palsey inability to move one side of

face, one shoulder, one side of tongue. Evaluation

Trismus to evaluate pterygoid involvement

CT/MRI

FNA in parotid tumors 90% sensitive and >95%specific

Never perform incisional or excisional biopsy


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Parotid Tumors

Lymph Nodes Rare in adenoid cystic

12% positive in clinically negative tumors. Size and grade are risk factors

>4 cm 20% occult mets vs 4% in smaller tumor

High grade 49% risk regardless of histologic type vs 7% for low orintermediate

Distant Spread Lung

25-35% risk for mucoepidermoid, adenoid cystic andmalignant mixed tumors.

Routine CXR


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Postoperative Radiation versus Surgery for Salivary

Gland Tumors: Results from the literature

SeriesSeries ##PTsPTs

FUPFUPlengthlength(y)(y)

PrognasticPrognasticfactorsfactors

LC 5yLC 5y

SS SS/R/R

SurvSurv 5y5y

SS SS/R/R

MSKCCMSKCC 9292 S 10.5S 10.5

S/R 5.8S/R 5.8

Stage I/IIStage I/II

Stage III/IVStage III/IVPositive nodesPositive nodes

HighHigh--GradeGrade

79 9179 91

17 5117 5140 6940 69

44 6344 63

96 8296 82

9.5 519.5 5119 4919 49

28 5728 57

JHJH 8787 All patients All patients 58 9258 92 59 7559 75

MDACCMDACC 155155 7.57.5 All patients All patients 58 8658 86 5050--56 6656 66--7272

PMHPMH 271271 1010 All patientsAll patients -- 29 6829 68(RFS)(RFS)


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Submandibular tumor

Clinical presentation Asymptomatic mass

Painful mass as enlarges

Cranial nerve palsey decrease sensation in ipsilateral lower

teeth, lip and gums, inability to move ipsilateral oral tongue orinbality to move part of face.

Evaluation CT/MRI help to distinguish a pseudomass

FNA in submandibular tumors useful only if reveals amalignancy.

All lesions approached with a submandibular triangle dissection

Almost never perform incisional or excisional biopsy.


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Submandibular Tumors

Lymph Nodes

28% risk in submandibular tumors

Lvl I, II and III most common sites

Distant Spread

Lung >bone and liver


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Sublingual Tumors

Clinical presentation

Asymptomatic swelling in floor of mouth

Cranial nerve palsey ipsilateral loss of sensation

of one side of tongue.

Evaluation

CT/MRI

Most tumors are malignant so FNA only useful ifmaligant

Always resect with a formal cancer surgery


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Sublingual Tumors

Lymph Nodes

Higher risk of LN spread then parotid tumors

Lvl I is first site of drainage

Distant Spread

Lung > bones and liver


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Treatment

Surgery -Parotid 90% confined to superficial lobe perform superficial

parotidectomy

If adjacent to deep lobe - total parotidectomy

If invades adjacent soft tissue radical parotidectomy

Never perform piecemeal excision in an attempt to preservefacial nerve

Nerve grafting can be performed and RT can start3-4 wkpost op without adverse affects

Freys syndrome (gustatory sweating) due to redirection ofparasympathetic and sympathetic nerve fibers to the dermalsweat glands


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Treatment

Surgery - Submandibular

Small tumor gland excision

ECE En bloc resection with extended supraomohyoid

neck dissection

Surgery Sublingual

Small and localized can resect without

submandibular gland Generally requires resection of submandibular

gland as well.


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Treatment

Radiation Surgically unresectable tumors

EBRT with photon and or electrons with

conventional or altered fractionation

Brachytherapy EBRT

Neutron therapy


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Treatment


EBRT

Equivalent control rates as for equivalent head and

neck squamous cell cancers

Early stage 71-100% control rates

Late and Recurrent 50-70%

Hyperfractionation

Wang and Goodman reported on 14 patients using 1.6 Gy bidto 65-70 Gy.

5 yr LCR 82%


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Treatment


Brachytherapy

Used frequently with recurrent or advanced disease

5 yr LCR 60% Neutron therapy

Biologic effect of neutrons less effected by hypoxia

Lethal effects less dependent on cell cycle

Repair of sublethal damage in malignant cells is less

RBE > 2.6

Severe late effect greater 17% versus 7%

Improved local control but no diff in overall survival


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Treatment

Postoperative Radiation Indications

Close surgical margins (deep lobe parotid tumors, facialnerve sparing)

Microscopically positive margin High grade including adenoid cystic

Involvement of skin, bone, nerve (gross or extensiveperineural invasion), tumor extension beyond capsule withperiglandular and soft tissue invasion

LN spread Large tumors requiring radical resection

Tumor spillage

Recurrence


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Treatment

Postoperative Radiation

LCR with surgery and post op RT

T1 100% T2 83% T3 80% T4 43%

Technique

Parotid

Electrons lateral en face

Mixed beam 50-80% electron weighting lateral enface or wedge pair.

Photons - wedge pair or IMRT


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Treatment

Technique

Portal margins Parotid

Superior top of zygomatic bone

Inferior hyoid bone thyroid notch

Anterior - 2cm ant to upper second molar

Posterior posterior to mastoid tip.

Lateral - 2 cm flash on cheek

Medial 2 cm medial from ipsilateral oropharyngeal area. Electron portal margins are 1 cm greater

Usually 12 MeV- 16 MeV energy used


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Treatment

Technique

Portal margins Submandibular

Superior 1cm above upper border of tongue

Inferior Hyoid bone-thyroid notch interspace

Anterior anterior aspect of mental symphysis

Posterior BOT- jugulodigastric nodal area

Lateral 2 cm flash of ipsilateral mandible

Medial midline of tongue


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Treatment

Technique

Portal margins Sublingual

Superior 1cm above upper border of tongue

Inferior Hyoid bone-thyroid notch interspace

Anterior anterior aspect of mental symphysis

Posterior posterior aspect of the ascending

mandibular ramus

Lateral 2 cm flash of ipsilateral mandible

Medial 2cm past midline


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Treatment

Dosage Primary treatment

Accelerated fractionation with a delayed

concomitant boost

Phase I 1.8Gy daily to 36 Gy

Phase II 1.8 Gy as in phase I in AM x 10 fractions to

54Gy and > 6hrs 1.6 Gy to GTVx 10 fractions to 16 Gy

Spinal cord dose < 45 Gy.

IMRT to 70 Gy for GTV 63 Gy CTV 1 and 56 Gy

CTV2


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Treatment

Dosage Post op treatment

Administered within 6 weeks of surgery

High Risk 2.0 Gy/fx to 60Gy and 1.8Gy/fx to 63Gy.

Small volume known microscopic disease 66 Gy.

Elective at risk 50 Gy (2.0Gy/fx) 54 Gy(1.8Gy/fx)

Gross residual 70Gy.


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Side effects

Salivary fxn

80% of saliva produced by major salivary glands

Loss of salivary fxn complete >35 Gy

Dose limit to spare salivary function is 26 Gy.

Trismus

TMJ and masseter muscle < 50Gy. PT during and

after treatment


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Adenoid Cystic Carcinoma

Post op RT always recommended

Post op RT of entire pathway of adjacent

cranial nerve to base of skull alwaysrecommended

Regional LN spread is 15% and elective nodal

irradiation is not standard

Surgery alone LCR 25-40% +RT 75%-80%


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Pleomorphic Adenoma

Benign tumor 75% of all parotid epithelialtumors.

Surgery is treament of choice

Multiply recurrent tumors can be treated with RT >3 local recurrences

Large lesion with surgically inadequite margin

Microscopically positive surgical margins

Macroscopic residual disease Malignant transformation

50-60 Gy dose


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Minor Salivary Tumors

Highest concentrations of the glands in theoral cavity, palate, nasal cavity and paranasalsinus

500-700 Glands

No glands located in the gingiva or anteriorhalf of the hard palate

50% malignant Adenoid cystic is most common malignant

histology seen.


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Quiz

What is the most common tumor of minor

salivary glands

A. Pleiomorphic Adenoma

B. Adenoid cystic carcinoma

C. Mucoepidermoid carcinoma

D. Squamous cell carcinoma


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Quiz

What are the borders of the parotid

gland?

Superior

Inferior

Anterior

Posterior

Zyogomatic arch

Hyoid bone

Ascending ramus of

mandible

Mastoid process


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Quiz

The most common parotid tumor is

A. Pleomorphic adenoma

B. Mucoepidermoid carcinoma

C. Adenoid cystic carcinoma

D. Detroit tigers


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Quiz

Most parotid tumors are ___________

A. Benign 60%

B. Benign 80%

C. Malignant 60%

D. Malignant 80%


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Quiz

All of the following are true regarding adenoid

cystic carcinoma except?

A. It rarely spreads to Lymph nodes

B. It is a common minor salivary tumor

C. It typically does not involve nerves

D. 40% develop pulmonary metastasis


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Quiz

Adenoid cystic of parotid s/p parotidectomy

with perineural invasion, what is treatment

field?

A. Post op bed

B. Post op bed and BOS

C. Post op bed and BOS and ipsilateral neck

D. Post op bed and BOS and bilat neck


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Quiz

What is treatment of choice for cystic

pleomorphic adenoma? After rupture or

residual?

Superficial parotidectomy. If intraop cystic

rupture, add post op RT


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Quiz

How are parotid tumors staged?

T1

T2

T3

T4

2cm

2-4 cm

Extraparenchymal, No

VII involvement 4-6cm

>6cm, BOS, CN VII


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Quiz

All of the following are indication for RT in

pleiomorphic adenoma except?

A. Deep lobe involvement

B. Large >5cm

C. Recurrent tumor

D. Positive margin


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Quiz

What seperates the superficial parotid from

the deep lobe?

Facial Nerve


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Quiz

Intraparotid lymph node and a single 3cm

neck node what is the most likely primary?

Skin

Parotid

i


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Quiz

True/False series. Indication for post-

op RT for parotid tumors Close but clear margin

on benign pleomorphic

adenoma < 3cm

Adenoid cystic with clear

margin

High grade

mucopidermoid

CN VII sacrifice for tumor

close to nerve but not

invading nerve

False

True

True

False


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Salivary Gland Tumorsds