francisco g. pernas, md faculty advisor: susan d. mccammon ... · distinct tumor types often share...

Francisco G. Pernas, MD

Faculty Advisor: Susan D. McCammon, MD

Grand Rounds Presentation

The University of Texas Medical Branch

Department of Otolaryngology

February 25, 2011

Outline

I. Case Presentation

II. Background on Parotid Malignancies

III. Anatomy/Epidemiology

IV. Workup of a patient

V. Types of Malignancies

VI. Areas of Controversy

VII. Conclusions

Case Presentation

H & P

42-year-old white woman

16 months prior had undergone resection for lesion in parotid (described as enucleation by patient) – Path/Op Report not available

No further treatment was offered at that time

Patient presents to ENT

Complains of regrowth mass in right facial area

Case Presentation

Weakness on right side of face

Pain in region required narcotics

Denies xerostomia, trismus, odynophagia, dysphagia, globus sensation

Case Presentation

PE:

No suspicious skin lesions

2.5-cm scar in right pre-auricular region

2.0-cm non-mobile rubbery mass in the right parotid gland

Erythema of surrounding skin

House-brackman facial nerve- II/VI

Lymphadenopathy in submandibular region and anterior triangle of neck

Case Presentation

What to do next?

Case Presentation

Issues:

Not sure of original path

Not sure of extent of first surgery

Facial weakness caused by surgery or tumor

Case Presentation

Discussion:

Should this patient be offered an FNA?

Imaging modality?

Facial N preservation?

Post-Operative XRT?

Case Presentation

Pt. was scheduled for total

parotidectomy and right selective neck

dissection of lymph node levels I-IV.

Tumors of Salivary Glands

History

RIOLAN 1648: Identified the glandular substance of

parotid

NIELS STENSON 1660: Identified the parotid duct in

sheep

THOMAS WARTON 1656 – Identified the submandibular

gland and duct

HEYFELDER 1825: Avoided the facial nerve after

parotidectomy

VELPEAU 1830: Identified trunk of facial nerve

BELL AND VELPEAU: Determined the facial nerve was

responsible for facial animation. Determined facial

sensation was from CN V.

Parotid Gland

Anatomy

Largest salivary gland

The parotid duct lies on an imaginary line between the external nares and the tragus of the ear.

Boundaries: external auditory canal, ramus of mandible, & mastoid process

Gland is encased in a sheath

Stensen’s duct – courses anterior to masseter muscle, transverses Buccinator, and exits orally along maxillary second molar.

Artificial division between the deep and superficial lobes by facial nerve.

Parotid Gland

Anatomy – Facial Nerve

Exits from stylomastoid

foramen

Divides into temporofacial

and cervicofacial

Terminal Branches:

Temporal/Frontal

Zygomatico-orbital

Buccal

Mandibular

Cervical

Parotid Gland

Surgical Anatomy – Facial Nerve

Tympanomastoid suture

Bisects angle between post

belly of digastric and ear canal

Tragal Pointer

1cm deep and inferior

Nerve lateral to styloid process

Superficial to retromandibular

vein

Retrograde dissection

Epidemiology

Malignant salivary gland neoplasms represent 3-4% of malignant head and neck disorders

Incidence of 1-2 per 100,000 individuals

Neoplasms arising in the minor salivary glands have a poorer prognosis than those primary in the parotids.

20-25% of parotid gland tumors are malignant

Average age of presentation is 56.6 years

History and Physical

Present with an incidentally noted mass

Pain

Nerve palsy, commonly CN VII, but

lingual and hypoglossal nerves may be

affected.

Presence of lymphadenopathy

Trismus, numbness, fixation may also

be present

Diagnostic Studies

CT (with contrast)

Requires contrast and radiation

Excellent detail of the tumor volume

Useful in evaluating the parapharyngeal space

Relation of tumor to vascular and bony structures helpful in surgical planning

Lymphatic survey

Diagnostic Studies

MRI

Does not require iodination or radiation

Excellent soft tissue detail

Superior in defining the tumor boundaries

Useful to determine if nerve involvement present

T1, low signal

intensity

T2, high signal

intensity

Diagnostic Studies

PET Scan

Useful in staging and follow-up

Rule out distant and regional

metastases

Predicted the nature of the

neoplasm in 69%

Demonstrated 100% sensitivity

for malignancy

False-positive rate of 30%

Role not yet well defined

Diagnostic Studies

Fine-Needle Aspiration

Biopsy

Efficacy is well

established

Accuracy = 84-97%

Sensitivity = 54-95%

Specificity = 86-100%

Safe, well tolerated

Pleomorphic Adenoma- FNA

Fine-Needle Aspiration Biopsy

Opponents argument:

Doesn’t change management

○ Often surgery regardless of reported

diagnosis

Obscuring final pathologic diagnosis

Frequency of “inadequate” sampling,

requires multiple biopsies, prolongs course

until definitive treatment, increases cost

Fine-Needle Aspiration Biopsy

Proponent’s argument:

Important to distinguish benign vs. malignant

nature of neoplasm

Preoperative patient counseling

Surgical planning

Differentiate between neoplastic and non-

neoplastic processes

○ Avoid surgery in a number of patients

Risk Factors for

Primary Salivary Malignancy

Increased risk:

Radiation exposure

Full-mouth dental x-rays

Rubber industry

Nickel compound/alloy

Hair dye

Silica dust

Kerosene cooking fuels

Vegetables preserved in salt

Decreased risk:

High intake liver

High intake dark yellow vegetables

Histologic Types

Mucoepidermoid Carcinoma 34%

Adenoid Cystic Carcinoma 22%

Adenocarcinoma 18%

Carcinoma ex pleomorphic adenoma 13%

Acinic cell carcinoma 7%

Squamous cell carcinoma 4%

Mucoepidermoid Carcinoma

Most common type

80-90% occur in the parotid gland

Female to male ratio of 4:1

Highest prevalence in 5th decade of life

Characterized histologically by a mixed population

of cell, mucin-producing cells, epithelial cells, and

intermediate cells.

Stain positive with Mucicarmine stain

Classified as low, intermediate, high grade based

on clinical behavior and tumor differentiation.


Low-grade tumors have a higher

proportion of mucous cells to epidermoid

cells.

High-grade mucoepidermoid carcinomas

have a higher proportion of epidermoid

cells difficult to differentiate from

scca.


Mucicarmine stain Characterized by islands having

squamous cells as well as clear cells

containing mucin and intermediate

cells.


Survival rates:

5 yr.

survival

15 yr.

survival

Low

Grade 70% 50%

High

Grade 47% 25%

Adenoid Cystic Carcinoma

More common in submandibular, sublingual and

in minor salivary glands

Presents equally frequent in women and men

Asymptomatic mass

Clinical course is indolent and protracted

Perineural spread, including discontinuous

spreading can occur along a nerve in 80%

Therefore adjuvant radiation to regional named

nerves is recommended

Lymphatic spread is uncommon


Microscopically, adenoid cystic

carcinoma has a basaloid epithelium

arranged in cylindric formations in an

eosinophilic hyaline stroma.


Subtype % Characteristics

Cribiform 44%

Swiss cheese pattern

of vacuolated area

(best prognosis)

Tubular 35% Cords & nests of

malignant cells

Solid 21% Solid sheets of cells

(worst prognosis)

Cribiform subtype

Adenocarcinoma

Aggressive behavior

25-60% nodal metastases

50% recur locally

Originates from excretory or striated ducts.

Histologically identified by mucicarmine stain for mucus & negative keratin stain

Polymorphous low-grade adenocarcinoma is a more benign subtype

Prognosis: 5 yr survival is 25-70%

Poor prognostic indicators: advanced stage, infiltrative growth pattern, abnormal DNA

Carcinoma Ex-Pleomorphic adenoma

75% occur in parotid gland

Arise from/in pleomorphic adenomas (a benign mixed tumor)

Associated with a rapid change in size of a previously stable tumor.

Histologically: mixture of epithelial and mesenchymal cells

Malignant component is purely epithelial

Classified as high grade

Prognosis: if treated prior to invasion, good.

5 yr. survival is <10%.

Carcinoma Ex-Pleomorphic adenoma

Treatment is surgical

resection with facial

nerve preservation,

neck dissection for

nodal disease, and

adjuvant

radiotherapy. Ductal structures (D) are randomly

scattered and lined by cuboidal or

columnar epithelium which usually

surrounded by myoepithelial cells

(M). Islands of well-differentiated

squamous cells with keratin (S) are

seen.

Acinic Cell Carcinoma

80-90% occur in parotid gland

Presents in 5th decade of life

Higher incidence in women

Low-grade malignancy

Two cell types: serous acinar cells (explains parotid gland preference) & clear-cytoplasm cells

Four histologic types: Solid, microcystic, papillary, & follicular

Prognosis at 5, 10 & 15 yrs is 78%, 63%, 44%

Acinic cell carcinoma

Round cells with

abundant

granular, blue

cytoplasm

Squamous Cell Carcinoma

Existence of true primary SCC of salivary glands debated

Present in elderly males

Commonly present in advanced stage

20% facial paralysis

40-70% nodal metastases

15-20% distant metastases

Must distinguish from mucoepidermoid carcinoma with immunohistochemical staining for mucin.

Must exclude extension from skin primary or mucosal primary

Neck dissection is indicated

Metastases to Parotid Gland

Lymph Nodes

Less than 10% of malignant salivary disorders are metastases from other sites

Most are lymphatic metastases from skin cancer of face, ear, scalp.

Most commonly SCC or Melanoma.

Elective superficial parotidectomy and neck dissection should be performed for primary melanoma of intermediate depth (1.5-4mm) located within periparotid drainage area.

TNM Staging

T1 Tumor less than 2cm

T2 Tumor between 2cm and 4cm

T3 Tumor greater than 4cm and/or extraparenchymal extension

T4a Moderately advanced disease, invades skin, mandible, ear or facial n.

T4b Very advanced disease, invades skull base, pterygoids or encases carotid

Areas of Controversy

FNA

PET-CT usefulness

Preferred modality of imaging.

Radiotherapy for unresectable tumors

Facial nerve preservation

LN Dissection

FNA

Remove cells by aspiration

Not able to visualize structure of tissue

George Papanicolaou (1883–1962) is

generally credited with the rediscovery

of cytopathologic examination

Extracts diagnostic information from the

appearance of individual cells and cell

clusters.

FNA

Among H&N sites, the parotid gland has

the highest FNA inaccuracy rates:

Sheer number of number and diversity of

salivary gland tumors.

Relatively uncommon – cytopathologist

experience limited.

Distinct tumor types often share some

overlapping morphologic features.

Some parotid carcinomas appear very bland

and nonthreatening at cellular level.

FNA

Should reliably:

Distinguish benign from malignant

Identify lymphoma

Cutaneous malignancy

Fine needle aspirationcytology in the management of a

parotid mass: A two centre retrospective study K. Balakrishnan et. al

6 yr study, N= 132

52 (46%) aspirates were suggestive of

the final diagnosis

35 (31%) were non-diagnostic

15 (13%) were sampling errors

11 (10%) FNAC results were misleading.



Sensitivity of FNAC in detecting

malignant disease was 79% (95% CI 61-

97%)

Specificity of 84% (95% CI 73-95%)

Positive predictive value of 68% (95% CI

48-88%)



Concluded:

Majority of neoplasms are benign and FNAC

appears better at predicting benign than

malignant disease.

Correctly identifying pleomorphic adenoma

as a benign tumour was 92%.

FNA did not reliably predict/dx lymphoma,

but may have avoided radical parotidectomy.

Value of the cytological diagnosis in

the treatment of parotid tumors. Jafari et. al.

6yr interval, N=110

concordance b/w cyto & histo was

observed in 82.1% of cases

benign or malignant concordance of the

tumors reached 92 percent.



Sensitivity of FNAC in detecting

malignant disease was 67%

Specificity of 96%

PPV was 80% and NPV was 93%.



Concluded:

In the majority of parotid tumors, there was a

good correlation between the FNA

cytological diagnosis and the

histopathological results

FNA provides an adjuvant tool in the

strategic and surgical approach of a parotid

tumor:

○ wider resection of parotid gland

○ cervical neck dissection

Value of Fine Needle Aspiration Biopsy of Salivary

Gland Masses in Clinical Decision-Making Heller et. al.

Complications of FNAB appear to be

rare.

No sign of tumor implantation by FNA.

FNA resulted in a change in the clinical

approach to 35% of the patients.

Surgery avoided in 27%

Lesser procedure performed in 8%

PET

Inflammatory lesions, warthin’s and

pleomorphic adenomas can have

increased FDG uptake.

Accuracy was 53%.

False-positive rate was 55% when the cut-off value for SUV was set at 3.5.

Keyes et al. reported an accuracy of 69%

False-positive rate of 30% for differentiation of benign and malignant masses using PET.

PET identified all 26 lesions:

All 12 malignant lesions

Correct categorization in only 69% of cases.

Thus, it was not as good as the more

conventional diagnostic methods, their

correct categorizations being 85% (clinical),

87% (CT/MRI), and 78% (FNAB) in the

same patients.

(*)The lesion contains high intensity area relative to CSF and that area

shows partial enhancement (yes) and no enhancement (no).

MRI vs CT

N=40 with a parotid mass

CT vs MRI

Concluded:

MRI better at distinguishing intrinsic vs

extrinsic

Inaccuracy rate of both MRI and CT was the

same regarding the tumor infiltration

MRI 3x more expensive than CT

CT and MRI are morphologically equivalent

studies and have the same diagnostic

potential in parotid tumors

MRI – Perineural Spread

Better at determining perineural spread

than CT

Criteria:

Replacement of nerve with tumor

Enhancement of gad

Increase in size of nerve

More sensitive and specific.

MRI was better in

determining cisternal

segment and

cavernous sinus

CT and MR imaging

were virtually

identical in

demonstrating

penineural tumor

below the skull base

T1 weighed MRI before and after GAD

is the study of choice if perineural

spread is suspected.

Fat suppression also beneficial around

skull base.

Generally, MRI indicated when nerve

involvement suspected.

Post-Operative XRT

166 Patients

34 yrs experience at MDA

Excluded patients with macroscopic

disease

Patients radiated to treat suspected

microscopic disease

Results:

9% local recurrence

10yr local control rates – 90%

Facial nerve sacrifice and ND were associated

with local failure

Concluded

Recommended postop XRT for:

High-grade histology

Recurrent disease

Inadequate surgical margins

Perineural invasion

Extension of disease beyond the gland

Nodal disease

Facial Nerve

Should the facial nerve be sacrificed

to achieve clear surgical margins?

Traditional management as been to preserve

facial nerve whenever possible.

1992 study of parotid adenoid cystic

carcinomas by Casler and Conley called into

question the customary surgical approach of

preserving the facial nerve.

Casler and Conley:

32 patient with nerve sacrifice

Normal pre-op function

Higher 15-yr survival rate (60%) than in

those patients in which nerve was

preserved.

But did not reach statistical significance

Retrospective chart review

Adenoid cystic from 1966-2007

Concluded:

Selective sacrifice when nerve impaired or where

tumor margins compromised seems to improve

local control and survival.

QOL significantly affected.

Pre-op FNA and CT extremely useful in

counseling patients.

Patients managed w XRT better local control.

Role of Neck Dissection

Traditionally surgery for primary site

with XRT to neck for clinically

negative neck in parotid malignancy

Literature Review

39 total publications from 1997-2007

83% (out of 871 patients) were staged

N0 by palpation and radiology

23% of ELND identified pathologic

nodes

Elective treatment by either (selective)

neck dissection or radiotherapy is,

therefore, widely practiced.

Regional recurrences are only 5% after

aggressive therapy.

Predictive Factors in N0 Neck

High tumor grade

Facial paralysis

Older age (>54y/o)

Perilymphatic invasion

Extraparotid extension

T3 or T4 disease

Caveats:

Most important factor is tumor grade

however this is usually unknown prior

pre-operatively

Still controversial how to treat N0 neck

Conclusions

Parotid carcinoma accounts for 3-4% of

H&N cancers

FNA important in counseling patient

Especially when FN is involved

Keep in mind variety of morphologies

(benign and malignant)

CT generally useful

MRI more useful when perineural

spread

Conclusions

PET may play a role but not initially

False positive in inflammatory process

Can not reliably distinguish benign from

malignant process

Post-Operative XRT indicated when

facial nerve is involved or in clinically

positive neck

Elective neck dissection maybe

indicated in certain circumstances

francisco g. pernas, md faculty advisor: susan d. mccammon ... · distinct tumor types often share...

Documents