Kj Lee 10Th Ed - Chapter 31 - Tumors Of The Temporal Bone

Front 1

What is the most common neoplasm of the middle ear?

Back 1

Glomus Tumor (paraganglioma) - aka chemodectoma

Front 2

What is the second most common neoplasm of the temporal bone/cerebellopontine angle?

Back 2

Glomus Tumor (paraganglioma)

Front 3

What are the three types of glomus tumors of the temporal bone?

Back 3

Glomus tympanicum (GT) - on tympanic promontory
Glomus jugulare (GJ) - along jugular dome
Glomus vagale (GV) - along Jacobson's and Arnold's nerves

Front 4

Are glomus tumors typically benign or malignant?

Back 4

Benign - only 2-4% malignant

Front 5

Are glomus tumors typically functioning or nonfunctioning?

Back 5

nonfunctioning - only 5% or less secrete neuroactive peptides

Front 6

What type of cells do glomus tumors arise from?

Back 6

chemoreceptor cells of the neuroendocrine system

Front 7

Which two classification systems are used for glomus tumors?

Back 7

Fisch
Glassock-Jackson - GT and JG only

Front 8

What are some symptoms in a pt with glomus tumor?

Back 8

Pulsatile tinnitus (80%) - GT and GJ
Hearing loss, conductive or mixed (60%) - GT or GJ
Aural fullness (32%) - GT and GJ
Hoarseness/dysphagia (15%) - GJ
Facial weakness (15%) - GT and GJ
Otalgia (13%) - GT and GJ
Functional tumors will present with palpitations, unexplained weight loss, and poorly controlled hypertension.

Front 9

Brown sign is seen in glomus tympanicum. What is this sign?

Back 9

blanching of middle ear mass with pneumatic otoscopy

Front 10

What laboratory workup is needed for glomus tumor workup?

Back 10

Urine for vanillylmandelic acid (VMA), metanephrines
- must be 5x higher than normal to be symptomatic
- used to exclude a functional component

Front 11

What is the imaging modality of choice for glomus tumors of the temporal bone?

Back 11

CT of the internal auditory canal

Front 12

What classic appearance is there of glomus tumors on MRI's?

Back 12

"salt and pepper" apperance due to flow voids within the tumor

Front 13

What must be done 24-48 hrs prior to surgical resection of a glomus tumor to improve intraoperative blood loss?

Back 13

four-vessel angiography with embolization of the feeding vessels

Front 14

How is glomus tympanicum treated?

Back 14

Glomus tumors in general are surgical diseases unless patient's comorbidities prevent operation.

Small glomus tympanicum tumors to the promontory can be removed via a transcanal or anterior tympanostomy approach
Large tumors require wider exposure via mastoidecetomy and posterior tympanostomy

Front 15

How is glomus jugulare treated?

Back 15

Glomus tumors in general are surgical diseases unless patient's comorbidities prevent operation.

Requires proximal control of the great vessels in the neck and the sigmoid sinus.
Large tumors = may require transposition of the facial nerve to exposure the tumor anteriorly
Method of choice for removal = Infratemporal fossa approach.

Front 16

What role does radiation play in glomus tumors of the temporal bone? What about stereotactic radiosurgery?

Back 16

Used in pts who cannot withdtand surgery or refuse surgery.
Used to prevent further tumor growth.
Likely efficacious due to fibrosis of the arterioles rather than direct effect on tumor cells.
Lower doses are sued for malignancies (15 Gy)

Stereotactic radiosurgery has reported 80% rate of tumor control.
***Risks: radiation-induced malignancy, osteoradionecrosis of the skull base, temporal lobe necrosis, cranial nerve injury

Front 17

What is the general info on endolymphatic sac tumors?

Back 17

locally aggressive tumors of the endolymphatic sac
can be sporadic or associated with von Hippel-Lindae (VHL) dz
- pts with VHL can have bilateral tumors and should be screened for this.

Front 18

What are the symptoms of a pt with an endolymphatic sac tumor?

Back 18

That of endolymphatic hydrops - likely due to obstruction of the normal flow and resorption patterns of endolymph
- SNHL
- Tinnitus
- Aural fullness
- Vertigo
- Late sx include facial paralysis, sx of brainstem compression, and lower cranial neuropathies.

Front 19

What will you see on CT imaging of an endolymphatic sac tumor?

Back 19

bony destruction of the posterior fossa plate with central calcification's
may extend into the mastoid as well

Front 20

What will you see on MRI imaging of an endolymphatic sac tumor?

Back 20

T1 - isointense to hyperintense when compared to cerebellar white matter
T2 - heterogenous (suggesting its highly vascular nature)
T1 with contrast - strongly enhancing

Front 21

What treatments do you recommend to a pt with an endolymphatic sac tumor?

Back 21

Surgery is the method of choice
Should involve removal of both surfaces of the dura to ensure complete removal
For small tumors, may use hearing sparing approaches, such as retrolabyrinthine-transdural approach.
For pts with nonserviceable hearing - translabyrinthine approach.
Large tumors can be preoperatively embolized to minimize blood loss

Front 22

What does a hemangioma of the temporal bone typically present like?

Back 22

It's a rare (<1% of temporal bone tumors) benign tumor that arises from blood vessels.
Typically associated with the facial nerve, particularly the geniculate ganglion

Slowly progressive or recurrent facial weakness with twitching.
Locally aggressive resulting in bony destruction.
- erosion into the cochlea results in SNHL
- dilation of the fallopian/internal auditory canal

Front 23

Which CT and MRI findings are seen in a pt with hemangioma of the temporal bone?

Back 23

CT- infiltrative erosive lesion centered at the geniculate ganglion
- may erode into cochlea or labyrinth
- intratumor calcifications are common

MRI - on T1 imaging hypo to isointense to brain and enhance avidly with contrast

Front 24

What treatment do you recommend to a pt with hemangioma of the temporal bone?

Back 24

Small lesiosn can be meticulously dissected free from the nerve when centered at the geniculate with full preservation of facial function.
Larger lesions or those with complete facial paralysis, tx is resection with nerve nerve grafting.

For IAC lesions, unless face is paralyzed, surgical tx involves decompression of the IAC as resection requires nerve resection and nerve grafting.

Front 25

What is a chordoma?

Back 25

Unusual locally aggressive neoplasm of the clivus; impacts the temporal bones by lateral extension of the tumor into the CPA or lower cranial nerves
Mets are rare

Front 26

From what does a chordoma develop from? Which cells are seen on histology?

Back 26

Develops from the notochord remnant

Histology: physaliferous cells

Front 27

How does chordoma present?

Back 27

With diplopia due to involvement of CN 6 as it passes through Dorello canal and headaches
- involvement of CN 5 also common

Five year survival rate = 51%

Front 28

How do you treat a patient who presents with chordoma?

Back 28

Surgical resection is the gold standard
- incomplete resection should be followed with adjuvant radiation
- biactive chemotherapeutic agents are in clinic trials)
- approaches include infratemporal fossa
- can also be managed with transnasal endoscopic resections in combination with lateral skull base approaches

Front 29

What is a choristoma? How does it present?

Back 29

by definition, it's a mass of histologically normal tissue in an abnormal location.
most common histologic type is salivary tissue
other types include lipoma's, and glial choristoma's (image)
presents with CHL and middle ear effusion

Tx is surgical excision

Front 30

What is the most common overall malignancy of the temporal bone?
What's the mc of the EAC?
What's the mc of the middle ear?
What's the mc of the pinna/conchal bowl

Back 30

What is the most common overall malignancy of the temporal bone? = SCCA
What's the mc of the EAC? = SCCA
What's the mc of the middle ear? = SCCA
What's the mc of the pinna/conchal bowl = basal cell ca

Front 31

What is the frequency of temporal bone SCCA?

Back 31

Rare tumor representing <0.2% of all H&N malignancies

Front 32

List a few possible risk factors or causations of temporal bone SCCA.

Back 32

Older literature associated chronic inflammator/otorrhea of the EAC or middle ears as in chronic otitis externa or chronic otitis media.
HPV
Prior radiation for unrelated dz

Front 33

What is the most common Sx of temporal bone SCCA?

Back 33

Otorrhea - most common complaints (60-80%)

Others include:
Otalgia (50-60%)
Hearing loss (20-60%)
Bleeding (5-20%)

Front 34

Any pt with primary SCCA of the ME/mastoid is automatically in T__ stage disease

Back 34

T3-T4 (advanced-stage dz)

Front 35

From the EAC, where is the pattern of spread for the following locations?
Anteriorly -
Laterally -
Medially -
Posteriorly -
Inferiorly -
Superiorly -

Back 35

Anteriorly - into the TMJ; parotid via direct bony erosion, invasion of the fissures of Santorini (cartilaginous EAC) or patent foramen of Huscke (bony EAC)
Posteriorly - into the mastoid via direct bony erosion
Laterally - into the meatus and conchal bowl
Medially - through the TM/annulus in the middle ear and attic
Inferiorly - into mastoid and stylomastoid foramen usually through direct bony erosion but may have perineural spread along the facial nerve into the foramen.
Superiorly - into the root of zygoma and intracranial space through direct bony erosion

Front 36

What is the 5-year prognosis of all pt's with SCCA of the temporal bone?

Back 36

30-45%

Front 37

In pts with SCCA of the temporal bone, at which T stages is adjuvant radiation recommended?

Back 37

T2, T3, T4

(in T1, no XRT if negative margins)

Front 38

What are the surgical options for treatment of SCCA of temporal bone?

Back 38

Lateral temporal bone resection (T1, T2)
Subtotal temporal bone resection (T3, T4)
Total temporal bone resection (T4) - rarely performed

Front 39

Why is en bloc total temporal bone resection rarely performed?

Back 39

due to significant operative mortality and postop morbidity

Front 40

What is the mc malignancy of the temporal bone in childhood?

Back 40

rhabdomyosarcoma

Front 41

What are the subtypes of rhabdomyosarcoma of the temporal bone?

Back 41

Embryonal (mc)
Alveolar
Boytroid
Spindle cell
Anaplastic

Front 42

What is the immunohistochemistry staining of rhabdomyosarcoma of the temporal bone?

Back 42

Desmin
MyoD1
Myogenin
Muscle-specific actin

Front 43

What is the mainstay of treatment for rhabdomyosarcoma of the temporal bone?

Back 43

Chemotherapy
- surgery is used for diagnostic biopsy
- radiation is used in conjunction with chem

Front 44

What are the top 3 cancers that mets to the temporal bone?

Back 44

1) breast
2) lung
3) GI