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Andrew Coughlin, MD

Faculty Advisor: Tomoko Makishima, MD, PhDThe University of Texas Medical Branch

Department of OtolaryngologyGrand Rounds Presentation

September 30, 2010

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History of CPA tumors

Discuss Relevant Anatomy

Epidemiology and Tumor Biology

Signs/Symptoms of CPA tumors

Brief overview of other CPA tumors

Treatment options

Present a case presentation

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Represent 10% of all intracranial tumors

Vestibular Schwannomas/Acoustic Neuromarepresent 78% of these tumors (1)

Differential Meningiomas Epidermoids

Other Cranial Nerve Schwannomas

Dermoid Tumors ( Chordomas, Teratomas)

Arachnoid Cysts Lipomas

Metastatic Tumors

Vascular Tumors (Hemangioma/Glomus Tumor)

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Autopsy series have shown incidence of 1.7 to2.7% (9,10)

MRI of 10,000 patients seen for non-otologic

reasons showed 7 positive cases or 0.07% (11) Denmark reports of 1.3 per 100,000 population

(12)

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Arise from Schwann cells within the IAC (1)

Equal frequency between inferior and superiordivisions of the vestibular nerve.

Arise from Scarpa Ganglion instead ofObersteiner-Redlich zone.

Scarpasganglion has highest density of schwanncells

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1. Neuregulin

Expressed by schwann cells to control proliferationand survival of schwann cells

2. Chemokines FGF, TGF-, VEGF, PDGF (14-17)

3. Sex Hormones (18)

Previous studies showed increased growth inpregnancy

Recent studies have not shown growth modulationor receptors for sex hormones

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Intracanalicular tumors1. Hearing Loss

2. Tinnitus

3. Vestibular dysfunction/Vertigo

CPA extension1. Disequilibrium/Ataxia

Brainstem Extension1. Midface Hypesthesia

2. Hydrocephalus (vision loss and headache)3. Other Cranial Neuropathies

*SNHL>tinnitus>disequilibrium>facial hypesthesia(13)

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Present in >85% of patients (19)

5% of patients with VS have no associatedhearing loss (20)

Speech discrimination out of proportion to HL Many notice difficulty on the telephone

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2ndmost common presenting sign

Often precedes hearing loss

Can be present without hearing loss

Can be high pitch, hissing, or a roar

Can localize to the opposite ear

Unilateral tinnitus should be evaluated

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Presenting symptom in 4% of patients

Larger tumors >2cm

Maxillary division 1st

Corneal reflex is the first to go

Facial weakness is rare

If present should assume a different type of tumor.

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Hitselberger Sign

Decreased sensation of EAC

Sensory VII more sensitive than Motor VII

Absent corneal reflex, nystagmus Hypesthesia to pinprick and touch

Weakness of Temporalis/Masseter muscles

Other cranial neuropathys Gait disturbances or difficulty with finger to

nose testing

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AAO-HNS classification

Class Pure tone average (0.5, 1,2, 3 kHz measured in dBHL)

Speech discriminationscore (%)

A 030 70100

B 3150 50100

C >50 50100

D Any 90 14

Word Recognition Scores

Class Word Recognition Score (%)

I 70100

II 5069

III 150

IV 0%

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**Positive test has 85% sensitivity for identifyingretrocochlear problem

Acoustic Reflex Threshold Increased (compared with cochlear norms) or absent

if retrocochlear process

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Sensitivity of 85 to 90% (25)

False Positive rate 10%

False Negative rate 18-30% for intracanalicular

tumors Number larger than in the past

Five waveforms are produced with the mostcommon being a latency in wave V compared

to the normal ear of >0.2msec. Recommended as a screening test for those

with low suspicion of vestibular schwannoma.

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70-90% of patients will show some abnormality(26)

50% of small tumors produce no abnormalities

(27) Caloric testing is commonly the only

abnormality

Inferior vestibular nerve tumors may be missed Superior nerve showed decrease in 98%

Inferior nerve shows decrease in only 60% (28)

Therefore not used as a screening test

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90% of vestibular schwannomas will enhancewith contrast

Frequently misses tumors that are not

intracanalicular and do not extend >5mm tothe CPA.

63% accuracy at diagnosis (29)

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VESTIBULARSCHWANNOMA MENINGIOMA

Centered on IAC

Globular appearance

Ice cream coneappearance in IAC

Bony erosion of IAC

Cystic degeneration orhemorrhage may bepresent

Extend along petrousridge

Sessile appearance

Dural Tail atperiphery

Iso/Hypointense on T1

Hypo to Hyperintenseon T2

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Signs and Symptoms (32)

Usually cause spontaneous nystagmus, facialhypesthesia, and gait ataxia

If inferior can cause hoarseness, dysphagia, tongueatrophy

If within the IAC can produce similar symptoms asVestibular Schwannoma

Hearing tests will show retrocochlear process iflarge enough, and 25% will have normal ABRs(33)

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Identical to cholesteatoma

Develop from epithelial rest cells

Slow growing

Commonly dont present until 20-30s

Arise adjacent to brainstem and infiltrate areasof least resistance

Can have irregular shape and infiltrate widely

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T2T1

T1 T1

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Histologically identical to VestibularSchwannomas

Characteristics

Rarely restricted to IAC Commonly have skip lesions

Generally involve part of geniculate ganglion

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Signs/Symptoms

Unilateral hearing loss

Tinnitus

Vertigo Aural fullness (if distal to geniculate)

Facial weakness is rare unless very large

Hearing tests show retrocochlear process but

impedance testing can show ipsilateral absentacoustic reflex

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Treatment is observation

If growth or facial nerve dysfunction

Resection of nerve with cable grafting

Translabyrinthine approach most commonly used Facial nerve decompression can be used if

paresis is developing

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Glomus Tumors Jugular Foramen Syndrome (IX,X,XI), Surgical excision

Hemangiomas Centered on geniculate, slow progressive facial weakness,

surgical excision with facial nerve grafting

Arachnoid Cysts Treatment is drainage

Cholesterol Granulomas Bright on T1 and T2, Drained via infralabyrinthine approach

Embryonic tumors (Dermoids, teratomas, chordomas) Excision with dysfunction

Primary Axial Tumors of CNS (glioma,hemangioblastoma, medulloblastoma) Surgical excision +/- radiation therapy

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Observation

Surgery

Stereotactic Radiosurgery

Radiation Therapy

**Generally tumors

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First Introduced Leskell in 1969 Gamma Knife

Uses 201 ionizing beams of gamma rays from cobalt 60 source

One session

LINAC Uses multiple beams from a linear accelerator

One session

Fractionated Radiotherapy Newer therapy to eradicate cells in different cell cycle stages

Multiple sessions

Goal is to stop tumor growth, not shrink or removetumor

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Hasegawa et al. 2005 (36)

317 patients

Median follow up 7.8 years

10 yr local control >92% Partial or complete radiographic response 62%

Progression free survival

96% if 15cm3p

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Freidman et al. 2006 (37)

390 patients

Median follow up 40 months

Median dose of 12.5 Gy 5- and 10-year local control 90%

Only 1% of patients required surgery for treatmentfailure

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Many different regimens studied

Dose 15-57.6 Gy/3-32fx

Median Follow ups of 48 months

5- year local control of >90%

**Relatively new idea so no long term outcomes

available

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Tumor Control 73.8 to 100% for Radiosurgery

91.4 to 100% for FSRT

Tumor Shrinkage 38 to 76.2% for Radiosurgery with single dose 34 to 76% for FSRT

Tumor Growth 0-26.2% for Radiosurgery

0-12.5% for FSRT Hearing Preservation

47-71% for Radiosurgery

57-100%for FSRT

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GK dose decrease from 16Gy to 12-13Gydecreased rates from 16% to 4.4% (41)

LINAC dose decrease of 16Gy to 12.5Gyshowed drop in neuropathy from 3.7% to 0.7%(37)

RS vs FSRT ranges of 2.4-29% vs 0-16% (38)

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1. Translabyrinthine Approach

2. Middle Cranial Fossa Approach

3. Retrosigmoid-Suboccipital Approach

**All will require discussion/collaboration withNeurosurgery

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ADVANTAGES DISADVANTAGES

Best hearingpreservation

70% speech

discrimination

Good exposure oflateral IAC, CPA, and

clivus Drilling is extradural

decreasing morbidity

Limited to tumors

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ADVANTAGES DISADVANTAGES

Can attack any size tumor

Hearing preservation

possible Wide exposure of

brainstem and lowercranial nerves

Neurosurgeon familiarity Consistent facial nerve

identification

Must be medially locatedwith

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Translabyrinthine

Total Resection 99.5 to 99.7% (44-45)

Near total resection (

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Serviceable hearing defined as class A/B or1/2 (24) Middle cranial fossa 51%

Retrosigmoid 31% Meyer et al. 2006 (50)

162 consecutive patients via MCF approach

Class A/B hearing preserved in 41%

56/113 (50%) with WR >70% preoperatively maintainedthat level. Tumor 0.2-1.0cm = 59%

Tumor 1.1-1.4cm = 39%

Tumor 1.5-2.5cm = 33%

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Reporting function at 6-12 month point is goldstandard

Preserved = Grade I/II (24)

Retrosigmoid 91% Middle Cranial Fossa 88%

Translabyrinthine 77%

Delayed paralysis (>72hrs after surgery)

Described by Grant et al. 2002 Incidence 5% (51)

79% regain postoperative function by 1 yr

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Mortality 1% due to neurovascular injury

Meningitis 1-8%

Aseptic more common than bacterial (bonedust/inflammation) S. aureus most common pathogen

Tinnitus 50% with preop tinnitus will have resolution postop

Balance abnormalities Occurs in most patients but gone by 6-9 months

Seizure/Hydrocephalus/Stroke (24) Rare and

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Myrseth et al 2005 (53) Retrospective review 189 patients tumors 3cm

86 by microsurgery vs. 103 by GK

5.9 year mean follow up

Local control rates of 89.2% Surgery vs 94.2% GK

HB 1-2 in 79.8% Surgery vs 94.8% GK p=0.0026

Quality of life significantly lower in surgery groupcompared to gamma knife group

*MCF approach was not utilized

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Pollock et al. 2006 (54) Prospective cohort of 82 patients unilateral VS

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Vestibular schwannomas are the most commonCPA tumor

Unilateral Tinnitus or SNHL must be evaluated Tumors

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55 y/o female with 2 year history of falls anddisequilibrium

Falls are now progressive and daily

Denies true vertigo just imbalanced Also has tinnitus, neck spasms, and migraines

She denies any hearing loss but family feels

otherwise

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PMHx: HTN, Hypothyroidism

PSHx: Partial hysterectomy and R thyroid lobectomy

FHx:

Noncontributory SHx:

45pack year history of smoking, -EtOH

Medications: HCTZ, metoprolol, sydol prn, soma, and ambien prn

Allergies: Sulfa

ROS: Otherwise negative. No vision or constitutional problems

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1. Finger to nose and gait ataxia

2. Essentially normal hearing3. ENG positive for left lateral canal

weakness

4. 2cm tumor, no hydrocephalus

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Patient had previous MRI 2005 showing notumor

Therefore it is decided that we perform

suboccipital craniotomy for excision of tumor

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Tumor

RetractedCerebellum

TentoriumCerebelli

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Tentorium

Cerebelli

Tumor

RetractedCerebellum

CNVII/VIIIComplex

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CN V

TentoriumCerebelli

Tumor

RetractedCerebellum

CNVII/VIIIComplex

CN VI

AICA

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Final Pathology: Meningioma

No complications at this point

Tuning forks 256hz and 512hz normal

HB I immediately and 72 hours postoperatively

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28. Linthicum FH. Electronystagmography findings in patients with acoustic tumors. Semin Hear 1983;4:4753.29. Welling DB, Glasscock ME III, Woods CI, et al. Acoustic neuroma: a cost-effective approach. Otolaryngol Head Neck Surg 1990;103:364370.30. Press GA, Hesselink JR: MR imaging of cerebellopontine angle and internal auditory canal lesions at 1.5T. AJR Am J Roentgenol1988; 150:1371.31. Shelton C, Harnsberger HR, Allen R, et al. Fast spin echo magnetic resonance imaging: clinical application in screening for acoustic neuroma. Otolaryngol Head

Neck Surg 1996;114:7176.32. Granick MS, Martuza RL, Parker SW, et al. Cerebellopontine angle meningiomas: clinical manifestations and diagnosis. Ann Otol Rhinol Laryngol 1985;94:3438.33. Selters WA, Brackmann DE. Acoustic tumor detection with brain stem electric response audiometry. Arch Otolaryngol 1977;103:181187.34. House WF: Translabyrinthine approach. In: House WF, Leutje CM, Doyle KJ, ed.Acoustic Tumors, San Diego: Singular Publishing; 1997:171-176.35. Charabi S, Thomsen J, Mantoni M, et al. Acoustic neuroma (vestibular schwannoma): growth and surgical and nonsurgical consequences of the wait-and-see policy.

Otolaryngol Head Neck Surg 1995;113:514.36. Hasegawa T., Fujutani S., Katsumata S., et al: Stereotactic radiosurgery for vestibular schwannomas: analysis of 317 patients followed more than 5

years. Neurosurgery57. 257-265.200537. Friedman W.A., Bradshaw P., Myers A., et al: Linear accelerator radiosurgery for vestibular schwannomas. J Neurosurg105. 657-661.2006.38. Likterov I, Allbright RM, Selesnick SH: LINAC radiosurgery and radiotherapy treatment of acoustic neuroma. Otolaryngol Clin N Am2007; 40: 541-570.39.

Prasad D., Steiner M., Steiner L.: Gamma surgery for vestibular schwannoma. J Neurosurg92. 745-759.2000.40. Andrews D.W., Suarez O., Goldman W., et al: Stereotactic radiosurgery and fractionated stereotactic radiotherapy for the treatment of acoustic schwannomas:comparative observations of 125 patients treated at one institution. Int J Radiat Oncol Biol Phys50. (5): 1265-1278.2001.

41. Kondziolka D., Lunsford D., McLaughlin , et al: Long-term outcomes after radiosurgery for acoustic neuromas. N Engl J Med1998, 339: 1426-1433.42. Roland PS, Eston D. Stereotactic radiosurgery for acoustic tumors. Otolaryngol Clin North Am 2002;35:343355.43. Bennett M, Haynes DS: Surgical approaches and complications in the removal of vestibular schwannomas. Otolaryngol Clin N Am2007; 40: 589-609.44. Shelton C. Unilateral acoustic tumors: how often do theyrecur after translabyrinthine removal? Laryngoscope 1995;105:958966.45. Thedinger BA, Glasscock ME III, Cueva RA, et al. Postoperative radiographic evaluation after acoustic neuroma and glomus jugulare tumor removal. Laryngoscope

1992;102:261266.46. Pace-Balzan A, Ley RH, Ramsden RT, et al. Growth characteristics of acoustic neuromas with particular reference to the fate of capsule fragments remaining after

tumor removal: implications for patient management. In: Tos M, Thomsen J, eds. Proceedings of the first international conference on acoustic neuromaAmsterdam:Kugler. 1992:701703.

47. Bloch D, Oghalai JS, Jackler RK, et al. The role of less than complete resection of acoustic neuroma. Otolaryngol Head Neck Surg 2004;130:104112.48. Friedman RA, Kesser B, Brackmann DE, et al. Long-term hearing preservation after middle fossa removal of vestibular schwannoma. Otolaryngol Head Neck S urg

2003;129:660665. 99.49. Ebersold MJ, Harner SG, Beatty CW, et al. Current results of the retrosigmoid approach to acoustic neurinoma. J Neurosurg 1992;76:901909.50. Meyer T.A., Canty P.A., Wilkinson E.P., et al: Small acoustic neuromas: surgical outcomes versus observation or radiation. Otol Neurotol2006, 27(3): 380-392.51. Grant GA, Rostomily RR, Kim K, et al. Delayed facial palsy after resection of vestibular schwannoma. J Neurosurg 2002;97:9396.52. Harsha W.J., Backous D.D.: Counseling patients on surgical options for treating acoustic neuroma. Otolaryngol Clin North Am2005, 38(4): 643-652.53. Myrseth E., Moller P., Pederson P.H., et al: Vestibular schwannomas: clinical results of quality of life after microsurgery or gamma knife

radiosurgery. Neurosurgery2005, 56(5): 927-935.54. Pollock B.E., Discoll C.L.W., Foote R.L., et al: Patient outcomes after vestibular schwannoma management: a prospective comparison of microsurgical resection

and stereotactic radiosurgery. Neurosurgery2006, 59(1): 77-85.