GLOMUS TUMOR- also known as chemodectoma or paraganglioma

1. GLOMUS TUMOR
[CHEMODECTOMA]
PRESENTER: DR MONICA P
MD Radiation oncology

2. GLOMUS TUMORS:
• Glomus bodies are found in the jugular bulb and along the tympanic [Jacobson] and auricular [Arnold]
branches of the CN X in the middle ear or in other anatomic sites.
• GTs are also known as chemodectomas or paraganglioma
• They consist of large epitheloid cells with fine granular cytoplasm embedded in a rich capillary network and
fibrous stroma with reticulin fibres, which deruve from embryonic neural crest cells.
• Mean age at diagnosis : 45yrs for carotid body tumors and 52yrs for glomus tympanicum.
• More common in females than males, may be familial, incidence may be influenced by hereditary syndromes
including PGL1-5, MEN2, NF1

3. CLINICAL PRESENTATION:
• In middle ear  ear ache, discomfort  pulsatile tinnitus, hearing loss, cranial nerve paralysis
• Involves middle crania fossa temporo-parietal headache, retro-orbital pain, proptosis, paresis of CN V, VI
• Posterior fossa involved  occipital headache, ataxia, paresis of CN V to VII, IX, XII
• Invasion of jugular foramen  paralysis of CN IX, X, XI
• Chemodectoma of carotid body  painless slowly growing mass in the upper neck.

4. GLASSCOCK-JACKSON CLASSIFICATION OF GLOMUS TUMORS
GLOMUS TYMPANICUM
I: small mass limited to promontory
II: tumor completely filling middle ear space
III: tumor filling middle ear and extending into the
mastoid
IV: tumor filling middle ear, extending into the
mastoid or through tympanic membrane to fill the
external auditory canal, may extend anterior to
carotid
GLOMUS JUGULARE
I: small tumor involving the jugular bulb, middle
ear and mastoid
II: tumor extending under internal auditory canal,
may have intracranial canal extension
III: tumor extending into the petrous apex, may
have intracranial canal extension
IV: tumor extending beyond the petrous apex into
the clivus or infratemporal fossa, may have
intracranial canal extension

5. CLASSIFICATION: Modification of McCabe and Fletcher classification of Chemodectomas [GTs]:
GROUP I: TYMPANIC TUMORS
Absence of bone destruction on X-ray
of the mastoid bone and jugular fossa
Absence of facial nerve weakness
Intact eighth nerve with conductive
deafness only
Intact jugular foramen nerves [CN IX,
X & XI]
GROUP II: TYMPANOMASTOID
TUMORS
X-ray e/o bone destruction confined to
the mastoid bone and not involving the
petrous bone
Normal or paretic seventh nerve
Intact jugular foramen nerves
No e/o involvement of the superior bulb
of the jugular vein on retrograde
venogram
GROUP III: PETROSAL AND
EXTRAPETROSAL TUMORS
Destruction of the petrous bone, jugular
fossa and/or occipital bone on x-rays
Positive findings on retrograde
jugulography
e/o destruction of the petrous or
occipital bones on carotid arteriogram
Jugular foramen syndrome [paresis of
CN IX, X, or XI]
Presence of metastasis.

6. DIAGNOSTIC WORKUP:
• History and physical examination, ENT examination
• Imaging 
o CECT to define tumor extent and possible CNS involvement
o MRI with gadolinium
o Aretriography to determine B/L involvement and collateral cerebral blod flow [optional]
o Jugular phlebography [optional]
o Gallium-68-DOTATOC PETCT  as GTs show high levels of somatostatin receptor [SSTR] subtypes 2 & 5,
this scan was shown to detect SSTR-expressing tumors with high sensitivity and specificity.
• Biopsy of glomus tumors may result in severe hemorrhage.
• Laboratory studies: CBC, Blood chemistry profile, urinalysis
• Special test:
o Audiograms  to establish baseline hearing loss
o Histologic staining  to determine presence of catecholamines

7. MANAGEMENT:
• Surgery is generally selected for small tumors that can be completely excised.
• Glomus tympanicum tumors excision via tympanotomy or mastoidectomy.
• Percutaneous embolization of a low-viscosity silicon polymer has been used frequently as preoperative
preparation of the tumor embolization of feeding vessels allows meticulous microsurgery with virtually
complete hemostasis.
• GTs arising in jugular bulb  surgery is piece-by-piece removal accompanied by significant intraoperative
bleeding with damage to adjacent neurovascular structures and requires more complex surgical approaches
involving the base of the skull.
• Local tumor control rate with surgery alone – 60%

8. RADIATION THERAPY:
• Tumors with destruction of petrous bone, jugular fossa, or occipital bone or patients with jugular foramen
syndrome are more reliably managed with irradiation.
• Dose: 45Gy to 55Gy / 1.8 to 2Gy per fraction (by IMRT)
• SRS dose: 12.5 to 20Gy per fraction with less complications compared to conventional therapy, hence, use of
SRS is preferred in Glomus tumors.

9. Objective:
1) Perform a meta-analysis of the available data on the outcomes of stereotactic radiosurgery (SRS) for the
treatment of temporal bone glomus tumors (GT), and
2) evaluate the collective outcomes of SRS treatment with respect to tumor control
15 Studies were included in this meta-analysis

11. A variety of modalities, including gross total resection, subtotal resection, conventional or
stereotactic radiotherapy including gamma-knife, embolization, and wait-and-scan strategy
can be considered.
The aim of this study was to compare long-term outcomes of different primary treatment
modalities in temporal bone paragangliomas

12. • Sixty-eight patients with TBP were treated between 1976 and
2018 at the Vienna General Hospital by the otolaryngology and
neurosurgical departments.
• Nine patients were excluded due to insufficient documentation,
resulting in 59 included patients.
• Two patients were lost to FU, resulting in 57 patients with
long-term observation time period of 7 (median; interquartile
range, IQR 2–15 years).
• Treatment options consisted of conventional radiotherapy (RT)
or gamma-knife radiosurgery (GKRS), subtotal resection
(STR) or total resection, single embolization, wait and-scan
strategy, or a combination of the above.
• In case of primary irradiation therapy, the respective radiation
dose in patients with primary conventional RT ranged from 43
to 60 Gy and GKRS from 22 to 28 Gy. Radiation dose in all
adjuvant RT cases ranged between 48 to 54 Gy within the
conventional RT group and 26 to 30 Gy in case of GKRS.

13. In conclusion, we propose surgery as a treatment option for patients with small tumors due to a high control rate and
less CN deficits compared to larger tumors.
Although patients with Fisch C and D temporal bone paraganglioma can be treated surgically, only subtotal
resections are possible in many cases