This document discusses tumors of the cerebellopontine angle and middle ear. It begins by defining the cerebellopontine angle and its boundaries. The most common tumors of this area are then described, including acoustic neuromas, meningiomas, and schwannomas. Symptoms, investigations, and management are outlined for these lesions. The document also discusses glomus tumors, the most common middle ear neoplasm, describing its pathology, spread, clinical features, and treatment.

1. TUMORS OF MIDDLE EAR
&
CP ANGLE
Dr. Sithananda kumar. R

2. Objectives
• To define boundaries of cerebellopontine angle
& jugular foramen
• To know the differential diagnosis for CP angle
mass
• To know the approach to evaluate and manage
a case of CP angle mass
• To know the evaluation and management of
jugular foramen lesions

3. TUMORS OF CP ANGLE

4. Cerebellopontine Angle
• Area of the lateral (quadrigeminal) cistern
containing CSF, arachnoid tissue, cranial
nerves and their associated vessels.
• Borders
Anterior –petrous part of temporal bone
Posterior – cerebellum
Superior-pons cerebellar peduncles
Inferior – cerebellar tonsils

6. INTERNAL ACOUSTIC MEATUS

7.  ACOUSTIC NEUROMA
 MENINGIOMA
 EPIDERMOID (CHOLESTEATOMA)
 ARACHNOID CYST
 SCHWANNOMA OF OTHER CRANIAL NERVES (E.G. CN V > VII > IX,
X,XI)
 GLOMUS TUMOUR
 METASTASIS

8. ACOUSTIC NEUROMA
Misnomer
other names- vestibular schwanoma,
Neurilemmoma
Doesn’t arise from acoustic nerve
Not a neuroma
Arise from Schwann cells-schwanoma
Arises from vestibular nerve

9. Vestibular schwanoma
6 % of all Intracranial tumors tumors
80 -90% of CPA tumors
95% Sporadic (unilateral)
5% -assoc with Neurofibromatosis type 2 (B/L)
No known race, gender predilection
age group of 40-60 years.

10. VESTIBULAR SCHWANOMA
Sporadic Type
95% of all vestibular
schwannomas
Unilateral
not associated with NF
seen in 5th -6th decade
Familial Type
5% of all vestibular
schwannomas
bilateral
Associated with NF-II
Seen in younger age groups

11. Genetics
 NF 2 Gene found at 22q12
Tumor suppressor gene preventing Schwann cell
proliferation
 Sporadic Variety (95%)
Hypothesized that there are two hits to the normal NF
gene
 Neurofibromatosis type II
Autosomal Dominant
Inherit one abnormal and one normal gene with one hit
to the normal allele.
Blood tests available to screen family members.

12. PATHOLOGY
Benign, encapsulated, extremely slow-growing
tumour of the 8th nerve
Arises from Schwann cells
Equal incidence from superior and inferior
vestibular nerve.
Arises within in the IAC in the region of scarpa’s
ganglion which has the highest density of
Schwann cells.

13. PATHOLOGY
Smooth surface , bright yellow to grey colour
Unencapsulated
Large tumors have cystic component

14. Microscopy /Immunohistochemistry
• Antoni A- densely packed cells with small spindle
shaped nucleus
• Antoni B- loosely arranged vacuolated pleomorphic
cells
• Verocay body- whorled or palisading appearance
Antoni A cells
• Positive for vimentin, S-100 and neuron specific
enolase

16. Classification
Depending on the size, the tumour is
classified as:
• canalicular (when it is confined to IAC)
• Small size (up to 1.5 cm)
• Medium size (1.5 to 4 cm)
• Large size (over 4 cm)

17. Phases of Tumor Growth
Intracanalicular:
hearing loss, tinnitus, vertigo
Cisternal:
Worsened hearing and disequilibrium
Compressive:
Occasional occipital headache
CN V:Midface and corneal hypaesthesia
Hydrocephalic:
Fourth ventricle compressed and obstructed
Headache, visual changes, altered mental status

21. Cochleo vestibular symptoms
Earliest symptoms -Tumour is still Intracanalicular
Caused by pressure on cochlear or vestibular nerve fibres or on the
internal auditory artery.
Progressive unilateral sensorineural hearing and loss tinnitus
Marked difficulty in understanding speech, out of proportion to the pure
tone hearing loss(characteristic)
Sudden u/l sensorineural hearing loss-rare.
Vestibular symptoms
Unsteadiness. True vertigo - seldom seen

22. Cranial nerve involvement
Vth nerve -earliest nerve to be involved.
Reduced corneal sensitivity, numbness or
paraesthesia of face.
Indicates that the tumour is roughly 2.5 cm in
diameter and occupies the cerebellopontine
angle.

23. • VIIth nerve.-Sensory fibres are affected early.
• hypaesthesia of posterior meatal wall
(Hitselberger's sign)
• loss of taste (as tested by Electrogustometry)
• Reduced lacrimation on Schirmer's test.
• Delayed blink reflex may be an early
manifestation(Motor fibres - affected late)

24. Brainstem involvement
Ataxia, weakness
numbness of the arms and legs with exaggerated
tendon reflexes
Cerebellar involvement - seen in large tumours
Finger-nose test / knee-heel test
Dysdiadochokinesia
Ataxic gait

25. Raised intracranial tension - late feature
Headache, nausea, vomiting
Diplopia due to VIth nerve involvement
papilloedema with blurring of vision

26. Audiological evaluation
• PTA-SNHL (marked in high frequencies)
• Speech audiometry - poor speech discrimination
• Roll-over phenomenon
• Recruitment phenomenon is absent.
• Short Increment Sensitivity Index (SISI) test will show a score
of 0-20% in 70-90% of cases.
• Threshold tone decay test shows Retrocochlear type of

27. Caloric test - diminished or absent response in 96%
of patients.
Neurological tests -Complete examination of
cranial nerves, cerebellar functions, brainstem
signs of pyramidal and sensory tracts should be
done.
Fundus –look for blurring of disc margins or
papilledema

28. MRI with gadolinium contrast - Gold standard for
diagnosis of acoustic neuroma.
Evoked response audiometry (BERA) - useful in
the diagnosis of Retrocochlear lesions.
In the presence of VIII th nerve tumour, a delay
of >0.2 msec in wave V between two ears is
significant

31. Surgery -treatment of choice
Surgical approach will depend upon the size
of tumour.
Various approaches are:
Middle cranial fossa approach.
Trans labyrinthine approach.
Sub occipital (retro sigmoid) approach.
Combined trans labyrinthine- sub occipital
approach.

36. X-knife or Gamma knife surgery.
Form of stereo-tactic radiotherapy
Radiation energy is converged on the tumour, thus
minimising its effect on the surrounding normal tissue.
X-knife surgery is done through linear accelerator and
gamma knife through a Cobalt-60 source
Causes arrest of tumour growth & reduction in its size.
In patients who refuse surgery
Have contraindications to surgery
In those with a residual tumor

37. Stereotactic surgery

43. Tumors of middle ear and mastoid
Primary Tumours
Benign: Glomus tumour
Malignant: Carcinoma, sarcoma
Secondary Tumours
From adjacent areas, e.g. nasopharynx, EAC ,
parotid.
Metastatic, e.g. from carcinoma of bronchus,
breast, kidney, thyroid, prostate and
gastrointestinal tract.

44. GLOMUS TUMORS

45. GLOMUS TUMOR
• Most common middle ear neoplasm
• Benign neoplasms of glomus bodies
–Glomus Tympanicum – Arnolds &
Jacobson’s nerves
–Glomus Jugulare – adventitia of jugular bulb
–Glomus vagale
–Carotid body tumour

46. Pathology
• Slow growing very vascular tumours
• 1% malignant
• 1 % secrete catecholamines
• Local bone destruction
• Can be very large at diagnosis

47. Often seen in the middle age (40-50 years).
Females are affected five times more.
Benign, non-encapsulated but extremely vascular
neoplasm.
Rate of growth is very slow
Tumour is locally invasive.

48. • Microscopically-masses or sheets of epithelial cells
which have large nuclei and a granular cytoplasm
• There is abundance of thin-walled blood sinusoids
with no contractile muscle coat, accounting for
profuse bleeding from the tumors.

49. Glomus Jugulare -arise from the dome of jugular bulb.
Invade the hypotympanum and jugular foramen, causing
neurological signs of IX th to XII th cranial nerve involt.
They may compress jugular vein or invade its lumen.
Glomus Tympanicum
They arise from the promontory of the middle ear and
cause aural symptoms, sometimes with facial paralysis.

50. Spread of Glomus Tumour
Initially fill the middle ear and later perforate through the
tympanic membrane -present as a vascular polyp.
may invade labyrinth, petrous pyramid and the mastoid.
may invade jugular foramen and the base of skull,
causing sixth to XII th cranial nerve palsies.
by spread through eustachian tube, it may present in the
nasopharynx.

51. may spread intra cranially to the posterior and
middle cranial fossae.
metastatic spread to lungs and bones is rare, but
seen in 4% of cases.
metastatic lymph node enlargement.

52. Clinical features
When tumour is intra tympanic
hearing loss and tinnitus-earliest clinical
feature
Hearing loss is conductive and slowly
progressive.
Tinnitus -pulsatile and of swishing in character,
synchronous with pulse
can be temporarily stopped by carotid

53. Otoscopy
A red reflex through intact tympanic
membrane.
"Rising sun" appearance is seen when tumour
arises from the floor of middle ear
Tympanic membrane appears bluish and may
be bulging.
"Pulsation sign" (Brown's sign) is positive

54. Signs
• Red/Purple mass behind tympanic membrane
• Hearing loss
• Brown’s sign
• Aquino’s sign
• Cranial nerve palsies

56. When tumour presents as a polyp
profuse bleeding from the ear either spontaneously or
on attempts to clean it.
Dizziness or vertigo
Facial paralysis may appear.
Examination reveals a red, vascular polyp filling the
meatus
It bleeds readily and profusely on manipulation or at
biopsy.

57. Cranial nerve palsies
late feature
IX th to XII th cranial nerves may be paralysed.
dysphagia & hoarseness
unilateral paralysis of the soft palate, pharynx and
vocal cord
weakness of trapezius and sternomastoid muscles.
Signs of intracranial involvement may also occur.

58. Auscultation with stethoscope over the mastoid
may reveal systolic bruit
Some glomus tumours secrete catecholamines
Headache, sweating, palpitation, hypertension
and anxiety

59. Rule of 10s
• 10% of the tumours are familial
• 10% multi centric
• 10% functional, i.e. they secrete
catecholamines

60. Investigations
• CT
• MRI
• Urinary/Serum catecholamines
– Metanephrine, VMA
• MIBG scan
• Audiology

61. Treatment
1. Surgical removal.
2. Radiation.
3. Embolization.
4. Combination of the above techniques.