GLOMUS TUMOUR

INTRODUCTIONGlomus temporale is the general name for glomus

tumours in the temporal bone.Depending on the location ,can be divided into 3

categories:1)Glomus jugulare2)Glomus jugulotympanicum3)Glomus tympanicum

These tumours are highly vascularized.

represent 0.6% of neoplasms of the head and neck

Glomus jugulare tumors are rare, slow-growing, hypervascular tumors that arise within the jugular foramen of the temporal bone.

Glasscock-Jackson ClassificationGlomus TympanicumType I: mass limited to the promontoryType II: mass fills the middle ear spaceType III: mass fills the middle ear space and extends into the mastoidType IV: mass fill the middle ear space, through the TM and fills the EAC and extends into the mastoid

Glasscock-Jackson ClassificationGlomus JugulareType I: involves the jugular bulb, middle ear and mastoidType II: Extends under the IAC and may have intracranial extensionType III: extends into the petrous apexType IV: extends beyond the petrous apex into the clivus or infratemporal fossa, +/- intracranial extension

Etiology

Glomus jugulare tumors originate from the chief cells of the paraganglia, or glomus bodies, located within the wall (adventitia) of the jugular bulb, and can be associated with either the auricular branch of the vagus nerve (Arnold nerve) or the tympanic branch of the glossopharyngeal nerve (Jacobson nerve).

Paraganglia are small (< 1.5 mm) masses of tissue composed of clusters of epithelioid (chief) cells within a network of capillary and precapillary caliber vessels.

Paraganglia develop from the neural crest and are believed to function as chemoreceptors.

The gene responsible for hereditary paragangliomas

has been localized to band 11q23.

Epidemiology

glomus tumors are the most common tumor of the middle ear and are second to vestibular schwannoma as the most common tumor of the temporal bone.

The female-to-male ratio is 3-6:1. More common on the left side, especially in

females. Most tumours occur in patients aged 40-70 years.

10% are familial, 10% are multicentric & upto 10% are functional.

HISTOPATHOLOGY

:Macroscopically, it appears lobular,

pulsatile and red-purple in colour.:Microscopically,

Composed of cluster of chief cells

(Zelballen) which contain

neurotransmitters (Norepinephrine), but rarely secrete.

Pathophysiology

Glomus tumors are un encapsulated, slowly growing, highly vascular, and locally invasive tumors.

Histologically glomus tumors has dense matrix of connective tissue among nerve fascicles. These tumors tend to expand within the temporal bone via the pathways of least resistance, such as air cells, vascular lumens, skull base foramina, and the eustachian tube.

They also invade and erode bone in a lobular fashion, but they often spare the ossicular chain.

Initially, the skull base erodes in the region of the jugular fossa and posteroinferior petrous bone, with subsequent extension to the mastoid and adjacent occipital bone

Significant intracranial and extracranial extension may occur, as well as extension within the sigmoid and inferior petrosal sinuses. Neural infiltration is also common.

Extent of glomus tumour

Fisch classification(based on extension of the tumor to surrounding anatomic structures) Type A tumor - Tumor limited to the middle ear cleft

(glomus tympanicum) Type B tumor - Tumor limited to the tympanomastoid

area with no infralabyrinthine compartment involvement

Type C tumor - Tumor involving the infralabyrinthine compartment of the temporal bone and extending into the petrous apex

Type C1 tumor - Tumor with limited involvement of the vertical portion of the carotid canalType C2 tumor - Tumor invading the vertical portion of the carotid canalType C3 tumor - Tumor invasion of the horizontal portion of the carotid canalType C4 tumor – Tumor reaching upto and involving foramen lacerum. Type D1 tumor - Tumor with an intracranial extension

less than 2 cm in diameterType D2 tumor - Tumor with an intracranial extension greater than 2 cm in diameter

Relevant Anatomy

The main blood supply is via the ascending pharyngeal artery from the external carotid artery (ECA) and branches from the petrous portion of the internal carotid artery (ICA).

The walls of the jugular foramen are formed anterolaterally by the petrous bone and posteromedially by the occipital bone. The canal follows an anterior, inferior, and lateral direction to exit the skull.

The jugular bulb is situated between the sigmoid sinus and the internal jugular vein. The lower cranial nerves are situated medial to the medial wall of the jugular bulb.

At the extracranial end of the jugular foramen, the ICA, internal jugular vein, and cranial nerves VII, X, XI, and XII are within a 2-cm area.

Pars venosa (posterolateral) sigmojugular

complex 10th and 11th cranial

nerve posterior meningeal

artery

Pars nervosa (anteromedial) inferior petrosal

sinus 9th cranial nerve

Tributaries

• Superior and inferior petrosal sinus• Occipital sinus• Mastoid and condylar emissary vein• Cavernous sinus and basilar plexus

through inferior petrosal sinus

• It connects transverse sinus to internal jugular vein.

Symptoms  EAR:Pulsatile  tinnitus

Conductive hearing loss

aural bleeding, aural discharge, middle ear mass,aural pain

Sensorineural hearing loss, vertigo –due to inner ear involvement.

CRANIAL NERVE INVOLVEMENT:Hoarseness, dysphagia due to Cranial neuropathy

Vernet’s syndrome( jugular foramen syndrome) comprising palsy of cranial nerves IX, X, XI

CATECHOLAMINE RELEASE:headache, perspiration, pallor, palpitation, anxiety,

HTN and nausea- due to catecholamine release.

•Intracranial involvement

Ataxia, headache, nausea, vomitting, visual disturbance, altered sensorium.

Thrombosis of sigmojugular complex:• Retrograde thrombosis of cavernous

sinus 3rd, 4th, 6th nerve palsy,proptosis,lid odema, venous congestion of fundus,conjuntival chemosis

• Raised intracranial pressure leads to seizures.

Signs

Otoscopic examination reveals a characteristic, pulsatile, reddish-blue tumor behind the tympanic membrane (RISING SUN SIGN)

PULSATION SIGN OR BROWN’S SIGN: When ear canal pressure is raised with siegle’s speculum, tumour pulsates vigorously and then blanches ; reverse happens with release of pressure.

Aural polyp

Audible bruit on auscultation over mastoid.

Unilateral palsy of soft palate, pharynx and vocal cord with weakness of trapezius and SCM muscles : late features

•Aim of investigations

Determine tumor size,type, extent Evaluation of multicentricity Asses intracranial involvement Asses major vascular involvement Know intracranial collateral

circulation Plan definitive treatment.

Investigations

Pure tone and speech audiometry: mixed conductive and sensorineural hearing loss.

24 hr urine collection for catecholamine metabolite assessment: level of VMA and metanephrine in a 24 hr urine sample may indicate neurosecretory activity.

Imaging study

Includes : CT scan

MRI and MRA

Four vessel angiography

Octreotide scintigraphy: for detection of multicentric tumours.

PET scan using 18F DOPA and 18FDG glucose

Biopsy is C/I

CT  Glomus 

jugulare tumors are enhancing softtissue masses  at the 

skull base.  These tumors are seen within the jugular foramen.

The demonstration of bone erosion of the jugular foramen and petrous apex is often a key finding in the diagnosis.

Glomus jugulotympanicum. 3D volumetric reconstructed image obtained from a CTA after IV contrast

Glomus jugulotympanicum. Coronal CT angiogram. Reformatted image after contrast administration demonstrates enhancing mass centered in the left middle ear, extending intracranially to the middle cranial fossa

Glomus jugulotympanicum. Axial CT images after administration of contrast with soft tissue algorithm demonstrated extensive bony erosion of the jugular bulb region with opacification of left mastoid sinus.

MRI 

It can  show intense tumor enhancement, and is  a key finding in the  diagnosis.

  A salt-and-pepper fine vascular pattern can be seen in

the tumors; this finding is suggestive of intrinsic tumor neovascularity, particularly on T2-weighted images

Coronal imaging can show tumoral relationships to the brainstem and skull base, and deep cervical soft-tissue structures

 

Glomus jugulotympanicum. Axial gadolinium-enhanced T1 MRI image with fat saturation demonstrating large enhancing tumor involving the temporal bone, middle ear, and peri-auricular region. The tumor is also seen extending into the left IAC.

Glomus jugulotympanicum. Axial gadolinium-enhanced T1 MRI with fat saturation demonstrating tumor along the length of the eustachian tube with extension into the left nasopharyngeal region.

ARTERIOGRAPHY Demonstrates  the feeding artery Jugulare tumors involve higher external carotid

branch vessels; the ascending pharyngeal, tympanic, and occipital arteries dominate the arterial blood supply.

Arteriovenous fistulae may be present.

Rarely, the internal carotid and vertebral arteries may contribute feeders to the neoplasms.

  

Lateral view of the carotid arteriogram of a 20-year-old woman . A norepinephrine-secreting glomus jugulare tumor with intracranial and cervical extension was identified on radiologic and arteriographic imaging. Arrows delineate the tumor blush. The arrowhead demonstrates a branch of the middle meningeal artery providing blood supply to the tumor.

Glomus jugulotympanicum. Angiogram image demonstrating the extensive vascular supply from multiple external carotid artery branches with diffuse tumoral blush.

Differential diagnoses include the following:ChordomaOtitis MediaEosinophilic Granuloma (Histiocytosis X)MeningiomaSchwannomaNeurofibromaChondrosarcomaCarcinoma (primary and metastatic)CholesteatomaOtosclerosisChronic mastoiditisCholesterol granulomaAneurysmAberrant intrapetrous internal carotid arteryIdiopathic hemotympanumArterious malformationProminent jugular bulb

Modalities of treatment

Wait and watch

Medical Mx

Surgical removal

Radiation

Embolisation

Combination of above techniques

1) Wait and watch

Most paragangliomas are slow-growing and benign, radiotherapy alone or no treatment at all is preferred in :

• Elderly (>65 years)• Small tumors• High risk of morbidity mortality

2) Medical therapy

Alpha-blockers and beta-blockers are useful for tumors secreting catecholamines.

They are usually administered for 2-3 weeks before embolization and/or surgery to avoid potentially lethal blood pressure lability and arrhythmias.

Successful treatment of pulmonary metastases with etoposide (VP-16) and cisplatin has been described.

a somatostatin analogue (octreotide) has been successfully used for growth control of somatostatin receptor–positive tumors.

3) Surgical removal

Surgery is the treatment of choice for glomus jugulare tumors. Surgical approach depends on the localization and extension of the tumor.

Fisch type A tumors can be excised by a transmeatal or perimeatal approach.

Type B tumors require an extended posterior tympanotomy.

Type C tumors require radical resection via a standard combined transmastoid-infratemporal or transtemporal-infratemporal approach with or without internal carotid artery (ICA) trapping, preceded by external carotid artery (ECA) embolization or superselective embolization. Surgery leads to therapeutic success in about 90% of patients. Intratumoral injection of cyanoacrylate glue has been proposed to control bleeding.

Large type D tumors need to be treated with a combined otologic and neurosurgical approach. An infratemporal approach with a skull base resection and a posterior fossa exploration are the most advisable in attempting to remove the entire tumor. Partial resection of the tumor needs to be followed by radiation and follow-up MRI/CT scanning.

Facial nerve transposition To gain adequate exposure

depending on size of tumor Short mobilization from 2nd genu for

small tumors Long mobilization from first genu for

medium and large tumors Reanimation, end-end/ rerouting,

interposition grafting for tumors involving facial nerve.

Preparation for extraluminal packing after mastoidectomy: a bone shell is left proximally on the sigmoid sinus and undermining is performed between the shell and the sinus to allow for Surgicel packing.

Schematic view illustrating deep bone removal down to the facial nerve. When bone removal is complete a fallopian canal bridge remains.

Once adequate tumor exposure is achieved, the sigmoid sinus is opened sharply and the intraluminal portion of the tumor is identified.

The intraluminal tumor is dissected from the intima of the sinus toward the jugular bulb.

Tumor in the hypotympanic portion is accessed through the middle ear cavity and can be delivered downward into the jugular bulb

Transjugular craniotomy for the single-stage removal of glomus jugulare tumors that have a substantial intracranial component.

4) Radiotherapy   Gammaknife  irradiation is used in:• Advanced age,poor candidates for surgery• Extensive disease• Residual or recurrance after surgery• Unacceptable morbidity, mortality

This procedure is expensive, and clear remission is not reported.

However ,It can control the tumor and prevent it from growing larger & decreases catecholamine release in functional tumours.

5) Embolization   Embolization  is a common technique used as the 

lone treatment option or as a precursor  to surgical excision. 

By starving the lesion of its blood supply and inducing necrosis embolization is often used to reduce blood loss.

Care must be taken to avoid inadvertent extracranial-intracranial embolization and the subsequent the risk of stroke.

    

Follow-up

Radiologic and, when indicated, endocrinologic monitoring for tumor growth or regrowth is indicated every 6 months to 1 year for 2 years and then, depending on the dynamics of the tumor behavior, every 2 years.

Complications

Complications of surgery include death, cranial nerve palsies, bleeding, cerebrospinal fluid (CSF) leak, meningitis, uncontrollable hypotension/hypertension, and tumor regrowth.

Complications of radiation include ICA thrombosis, secondary tumor development, pituitary-hypothalamic insufficiency, CSF leak, tumor growth, and radiation necrosis of bone, brain, or dura.

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