ANATOMY,PATHOLOGY,D/D,EVALUATION AND SURGICAL

APPROACH TO PARAPHARYNGEAL SPACE

ETIOPATHOGENESIS AND MANAGEMENT OF HEAD AND NECK PARAGANGLIOMAS

MADAN GUPTAJR ENT

PPS(parapharyngeal space tumor)

• Potential space• Inverted five-sided pyramid with its base towards the sphenoid bone

and its apex- horn of the hyoid bone (Heeneman, Gilbert and Rood,

Prestyloid vs Retrostyloid

• Key anatomical division of PPS• Tensor-vascular styloid fascia divides into

prestyloid and retrostyloid spaces• Anterolateral prestyloid/posteriormedial

retrostyloid• Used to make differential diagnosis based on

imaging

prestyloid Post styloid retropharyngeal

Artery maxillary ICA -

Vein - IJV -

Nerve Inf alveolar nerve IX,X,XI,XII -Lingual

Cervical sympatheticauriculotemporal

Lymph node - ++ +++

Glomus body - ++ -

Anatomical importance

• Pre styloid vs Poststyloid• least resistance- the naso- and oropharynx medially. the upper neck between the tail of the parotid

and the submandibular gland inferiorly.the retromandibular fossa posterolaterally.• The retropharyngeal space is connected with the

parapharyngeal space in an area just medial to the carotid sheath and its contents.

CONT….

• (node of Rouvière, 1927)- draining the nasopharynx, upper oropharynx and sinuses.

• Lincoln's highway.• Patey and Thackray (1956-157) coined the term

'stylomandibular tunnel' formed by the posterior margin of the ascending ramus of the mandible anteriorly, the styloid process and stylomandibular ligament behind and the base of the skull above. This tunnel resists pressure so that tumours of the deep lobe of the parotid gland assume a dumb-bell shape as they grow

CONT…

• upper deep cervical chain are connected superiorly to the node of Rouvière, while inferiorly they flow towards the jugulodigastric node, the node most commonly involved with metastatic disease from head and neck tumours

Evaluation

Carrau ,Mayer, Johnson ,nearly 50% of patients had a neckmass.

Pathology

Clinical symptoms

• Prestyloid– Serous otitis media– Voice change– Nasal obstruction– Dyspnea

• Poststyloid– Compress CN 9th, 10th, 11th, 12th or sympathetic chain– Hoarseness, dysphagia, dysarthria, Horner’s syndrome

• Cranial nerve paralysis, pain, trismus suggest malignancy

• Medial displacement of OROPHARYNX or lump behind the angle of mandible.

• Trismus • Syncope-may be associated with

glossopharyngeal neuralgia.• syndrome of inappropriate antidiuretic hormone

secretion or Schwartz-Bartter syndrome.• Detailed ENT evalution along with CRANIAL

NERVE examination.

FNAC

• equally applicable for neck lumps or lumps in the oropharynx.

• CT-guided FNAC• Pitfalls---- Rare tm—false + result Recurrence cases

CT scan

• Locates tumor to prestyloid vs poststyloid– Prestyloid tumor displace carotid artery posteriorly– Poststyloid tumor displace carotid artery anteriorly

• Fat plane between mass and parotid• Enhancement of lesion

– Schwannoma, paraganglioma, hemangioma, hemangiopericytoma, aneurysm

• Bone erosion due to malignancy• Limited soft tissue detail

MRI

• Most useful study• Relationship of mass and carotid more easily

seen than with CT• Characteristic appearances of tumor types on

MRI allows preoperative Dx in 90-95% of patients

Primary Tumors

• Three categories:• Salivary gland tumors• Neurogenic tumors• Miscellaneous tumors

Salivary Gland Tumors

• Most common PPS neoplasms: 40-50%• Prestyloid masses• Pleomorphic adenoma 80-90%• Mucoepidermoid most common malignant

Salivary Gland Tumors

• Located in prestyloid space• From deep lobe of parotid or minor salivary

glands• On CT or MRI a fat plane between the parotid

and a prestyloid mass indicates minor salivary gland origin

• Displace the internal carotid posteriorly

Pleomorphic adenoma

• Low signal intensity on T1• High signal intensity on T2• Displace carotid posteriorly

Neurogenic Tumors: 17-25%

• Benign lesions .Neurilemomas (Schwannomas). .Neurofibroma. .Paraganglioma. .Ganglioneuroma.• Malignant lesions .Malignant paraganglioma. .Neurofibrosarcoma. .Schwannosarcoma. .Ganglionblastoma

Schwannoma

• Most common neurogenic neoplasm• Vagus, sympathetic chain most common• Benign and slow growing• Generally don’t affect nerve of origin• Less than 1% malignant• Displace internal carotid anteriorly

Schwannoma

• High signal intensity on T2• Displace carotid anteriorly

Neurofibromas

• 3rd most common neurogenic tumor• From Schwann cells and fibroblasts• Unencapsulated (involve nerve)• Multiple• Part of Neurofibromatosis type I

Lymphoreticular Lesions

• The PPS and retropharyngeal nodes drain the oronaso, hypopharyngeal , posterior nasal cavity, and paranasal sinuses as well the posterior oral cavity.

• These are two groups, a superior lateral group (nodes of Rouviere) and an inferior medial group .

• Lymphoma is the most common• metastases from thyroid cancer, and sqamous cell

carcinoma, and renal cell carcinoma and osteogenic sarcoma may present in the nodes of the PPS

Other rare lesions of the PPS• They include:• Vascular (Hemangiopericytoma, angiosarcoma)• Muscle (Rhabdomyoma, Leiomyoma, rhabdomyosarcoma)• Connective tissue (Lipoma, fibroma, fibosarcoma, chondrosarcoma)• Meningioma, Meningiosarcoma.• Congenital (Branchial cleft cyst, dermoid, hemongioma,

lymphangioma,• arteriovenous malformation).• Pseudotumor sclerosing cervicitis, myositis, abscees, aneurysm.• Malignant invasion from surrounding structure• Distant metastases (Curtin,1987).

Axial T1W MR shows a homogeneous, infiltrating rhabdomyosarcoma in theleft PPS. The tumor has destroyed the left mandible, posterior maxillary sinus wall, and

skull base (from Som PM, Curtin HD. Parapharyngeal space. In: Head and NeckImaging: 1996: 943).

Coronal T2W MR scans show an infiltrating right PPS tumor (metastaticrenal cell carcinoma) eroding the skull base and invading the cavernous sinus and the

pterygoid muscles (from Som PM, Curtin HD. Parapharyngeal space. In: Head andNeck Imaging: 1996: 937).

Surgical approaches

• Transoral• Cervical with or without mandibulotomy• Cervical-parotid• Transparotid• Cervical-transpharyngeal “swing”• Infratemporal fossa• Transcervical-transmastoid

Transoral

• Has been used for small, benign tumors• Very limited exposure• Increased risk of tumor spillage, neurovascular

injury

Cervical

• With or without mandibulotomy

• Transverse incision at level of hyoid

• Submandibular gland displace or removed

• Increase exposure by releasing digastric, stylohyoid, styloglossus from hyoid, cut stylomandibular ligament, mandibulotomy

Cervical-parotid

• Extend cervical incision up infront of ear• Allows identification facial nerve• Divide posterior belly digastric • Divide stylomandibular ligament, styloglossus,

stylohyoid close to styloid process• Can use mandibulotomy

Cervical-parotid approach

Indications

• Can be used to remove majority of the parapharyngeal tumor– All deep lobe parotid tumors and extraparotid

salivary tumors– Low grade malignant tumors of deep lobe of

parotid– Many poststyloid tumors, including most

neurogenic tumors and small paragangliomas

Transparotid

• For deep lobe parotid tumors• Superficial parotidectomy• Facial nerve retracted• Dissect around mandible• May use mandibulotomy

Cervical-transpharyngeal

• “mandibular swing”• Large or highly

vascular tumors• Mandibulotomy

anteriorly, incise along floor of mouth to anterior tonsillar pillar

• Need a tracheotomy

indications

• All vascular tumors that extend into the superior portion of the parapharyngeal space

• Malignant tumor invaded skull base or vertebral body

Infratemporal fossa

• Preauricular lateral infratemporal fossa approach

• Skull base or infratemporal fossa involvement• Can combine with frontotemporal craniotomy

Transcervical-transmastoid

• Cervical incision carried postauricularly

• Mastoidectomy• Remove mastoid tip

exposing jugular fossa• Facial nerve may need to

be dissected from Fallopian canal

PARAGANGLIOMA

Paraganglia are specialized neural crest cells that arise in association with the autonomic ganglia..

Classification according to the anatomic sites -Glenner and Grimley :

1. Branchiomeric (Head and neck) paraganglia

2. Intravagal paraganglia

3. Aorticosympathetic paraganglia

4. Visceral autonomic paraganglia

BRANCHIOMERIC PARAGANGLIOMA

• Carotid body tumour• Jugulotympanic• Aorticopulmonary • Subclavian• Laryngeal• Coronary• Orbital

Pathology

• Type I: chief cells/granular cells• Type II: sustentacular cells

• "Zellballen“• Agrressive tumor

– ↓sustentacular cells– ↑ratio of immunohistochemical

analysis of chief cells & sustentacular cells

Pathology

• Type I– Catecholamines,

tryptophan-containing protein

– APUD/diffuse neuroendocrine system

Nuclear pleomorphism and cellular hyperchromatism are common & should not be considered as evidence of malignancy

Malignancy is based on the clinical finding of metastasis, not on histologic examination

Pathology

• Immunohisochemistry– Type I cells

• Neuron-specific enolase, chromogranin A, synaptophysin, serotonin

– Type II cells• S-100, glial fibrillary

acidic protein

Functional glomus jugulare

• Paraganglioma neuropeptides– Norepinephrine, serotonin, vasoactive intestinal peptide, neuron

specific enolase• 1-3% functional• Norepinephrine levels 4-5 times normal to elevate BP• Symptoms

– Headache, palpitations, flushing, perspiration , pallor , nausea

Functional glomus jugulare

• Labs– 24-hour urine

• Norepinephrine metabolites: vanillylmandelic acid, normetanephrine

• Excess epinephrine, metanephrine suspect pheochromocytoma• CT abdomen / selective renal vein sampling to r/o pheochromocytoma• Treatment- alpha and beta antagonists

Carotid body tm

• Haller –round reddish brown to tan structure found in adventia of the CCA

• Post-medial wall at bifurcation• Attached by “Mayer ligament”• Normal CB-3-5mm, <15gm

Etiopathogenesis

I. Chronic hypoxic stimulationII. Genetic familial 4 gene Encodes succinate dehydrogenase complex Defect -↑ intracellular concentration of

molecular hypoxic mediator and vascular endothelial growth factor---hyperplasia ,angiogenesis and neoplasia.

Pathogenesis

• Hypoxia, Hypercapnia , ↓ ph ↓ stimulation of type 1 cell ↓ ↑ autonomic activity ↓ ↑ resp rate,↑( heart rate & systemic

vascular tone & bp)

Imaging

• Jansen et alo Sequencial imaging doubling time-7.13 yrs growth rate- 0.83 mm/yrSHAMBLIAN: TYPE 1-ICA circumference -<180 * TYPE 2-ICA circumference->180*-<270* TYPE 3-ICA circumference->270*

Screening for carriers of SDH Gene

• Annual physical examination and measurement of blood pressure.

• Annual levels of urinary catecholamine and metanephrine

• Imaging of neck,thorax,abdomen and pelvis every 6-12 month by ct and or mri.

Management

• Surgery • positioned with neck extended• Subcutaneous injection with 40 mL of 1:100 000

adrenaline will aid haemostasis.• incision -skin crease 2 cm below the mandible• anterior border of the sternocleidomastoid is incised -

retracted - exposure of the carotid sheath.• common carotid artery is achieved after exposure and

dissection of the contents of the carotid sheath.

Complication

• Lack and collegue-15 % of CN palsy• Anand and collegue-1181 cases ICA injury-23% CNS complication-26%

Controversy over surgery for multicentric tumor

• B/l carotid body tm Save atleast one vagus Resect smaller first Unilateral preexisting CN palsy-functional side operated if

clinically observed Enlarged tm---RT may be option• Baroreflex failure syndrome B/L denervation-unopposed sympathetic outflow Compensation-baroreceptor aorta,regrowth of C sinus T/t-sodium nitroprusside- f/b-clonidine or

phenoxybenzamine

RADIATION

No. of CBT RT dose f/u period Local control

University of florida

23 35-48.5 Gy 1.5-10 yrs 96 %

Valdagni et al 13 46-60 Gy 1-19 yrs 100%

Jugulotympanic paraganglioma

• 2nd most common temporal bone tumor• Incidence = 1:1,300,000• Female to male ratio = 4:1• Median age of presentation = 50-60 years • Familial form a/w higher incidence of multicentricity (25-50%) • Malignancy rate < 5%• Slow growing, spread along pathways of least resistance

• Guild – paraganglia of the temporal bone as ovoid, lobulated bodies

measuring between 1-1.5mm in diameter , on the average, there are three such bodies in each ear

• Adventitia of the jugular vein ( glomus jugulare tumor) - 85% of cases• Jacobson’s nerve, a branch of the glossopharyngeal nerve ( glomus

tympanicum) - 12% of cases• Arnolds nerve , a branch of CN X, gives rise to glomus tympanicum in 3%

of cases• Blood supply ascending pharyngeal artery via inferior tympanic and

neuromeningeal branches

Jugulotympanic Paragangliomas

• Routes of spread– air cell tracts – eustachian tube– vascular lumens – neurovascular foramina including IAC– bone erosion

(watch for carotid crest separating the internal carotid from the internal jugular vein)

Presentation

• Pulsatile tinnitus (80%) • Hearing loss (60%)

– Conductive– Sensorineural (if labirinth eroded)

• Aural fullness • Red or reddish-blue mass behind TM• Vascular ear "polyp"• Brown’s sign• Aquino sign• Bruit over the mastoid

Presentation

• Cranial deficits (35%)– most commonly IX, X – VII, VIII, XI and XII can be affected– Vernet syndrome ( IX, X,XI)– Villaret syndrome (jugular foramen syndrome + Horner’s syndrome)– IV, V & VI impairment if cavernous sinus involved

• Ataxia if cerebellum is involved

Syndromes

• MEN IIA-Sipple’s syndrome– RET proto-oncogene chromosome 10– Medullary thyroid carcinoma, pheochromocytoma, parathyroid

hyperplasia• MEN IIB

– RET but different site– Mucosal neuromas

• Von Hipple-Lindau– Retinal angiomas, cerebellar hemangioblastomas

• Carney’s complex– Gastric leiomyosarcoma, pulmonary chondroma, extra-adrenal

functional paragangliomas

Familial paragangliomas

• 10% of cases• Chromosomes 11q13.1, 11q22-q23• Autosomal dominant• Genomic imprinting

– Only expressed if father passes gene• ? Higher incident with hypoxia due to altitude or medical conditions

Evaluation

• Fine cut CT of Temporal bone with contrast – bony partition between the jugular fossa

and hypotympanum– Caroticojugular spine– VII, cochlea and ICA– Excludes aberrant internal carotid artery /

high riding dehiscent jugular bulb– Sections down to the carotid body

excludes multicentric lesions

Audiogram with tympanometry

Evaluation

• MRI – intracranial and intradural extension– T1-weighted images, relationship with

neighboring neurovascular structures– diagnostic flow voids within the tumor

(salt and pepper pattern)

Vascular assessment

• 4 vessel arteriography – Multicentricity– Feeding vessels– Intrasinus and intravenous extension– Adequacy of flow in the contralateral

sigmoid and/or internal jugular vein– Embolization– BOT

• Evaluation of collateral blood supply to the brain – single-photon emission computed tomography (SPECT) with balloon

occlusion– transcranial Doppler, or angiography and balloon occlusion– xenon-enhanced computed tomography (ABOX-CT) scan

• predict the probability of cerebral ischemia when the ipsilateral ICA is sacrificed

• indicated when the risk for injury or the need for sacrifice of the ICA is high

ABOX-CT scan

• High sensitivity and specificity• Technique

– non-detachable balloon inflated in ICA for 15 minutes, while the awake patient is monitored for any neurological deficit

– Any neurological deficit cessation of the test high-risk pt– If no deficits balloon deflated pt taken toCT scan suite– A mixture of 32% xenon and 68% oxygen is administered via

facial mask for 4 minutes– CT scan demonstrates the cerebral distribution of xenon, which

reflects the blood flow {cubic centimeters (cm3) of blood flow per minute per 100 grams of brain tissue (cm3/min/100 g)}

ABOX-CT scan

• High sensitivity and specificity• Technique

– non-detachable balloon inflated in ICA for 15 minutes, while the awake patient is monitored for any neurological deficit

– Any neurological deficit cessation of the test high-risk pt– If no deficits balloon deflated pt taken toCT scan suite– A mixture of 32% xenon and 68% oxygen is administered via

facial mask for 4 minutes– CT scan demonstrates the cerebral distribution of xenon, which

reflects the blood flow {cubic centimeters (cm3) of blood flow per minute per 100 grams of brain tissue (cm3/min/100 g)}

Evaluation

• FNAC not advised• VMA, metanephrines, catecholamines level in 24 hr urine

• Abdominal CT if symptomatic ( flushing, HTN)• Scintigraphy techniques

– I-123 metaiodobenzyleguanidine – endocrine activity in glomus– Octreotide scintigraphy – multiplicity– 18F-PET & 18FDG PET- multiplicity

Glasscock-Jackson Classification

• Glomus Jugulare– I. Small tumor involving jugular bulb, middle ear, and mastoid– II. Tumor extending under internal auditory canal; may have

intracranial extension (ICE)– III. Tumor extending into petrous apex; may have ICE– IV. Tumor extending beyond petrous apex into clivus or infratemporal

fossa; may have ICE

Fisch Classification (1981)

• Class A - Middle ear, strictly promontory• Class B - Tympanomastoid area• Class C - Carotid

– C1 Carotid Foramen– C2 Vertical segment of carotid canal– C3 Horizontal segment of carotid canal– C4 Foramen lacerum and cavernous sinus

• Class D - Dural

• Extradural– De1: Intercranial Extradural extension < 2cm– De2: Intracranial Extradural extension > 2cm

• Intradural– Di1: Intracranial Intradural extension < 2cm– Di2: Intracranial Intradural extention > 2cm– D3: Metastasis

Pre-op embolisation

• For larger glomus jugulare tumors ( also for meningiomas)• Approximately 24 to 48 hours prior to surgery• Advantages

– reduce intra-op bleeding– improve intra-op visualization of the tumor – decrease surgical time

Studies have shown that the risk of ORN is low if the optimal dose of XRT of 35Gy/3weeks or 45Gy/4weeks is used

cranial nerve deficits

vascular injury

bleeding CSF leak

tumor regrowthlate-onset

cranial nerve defects

osteoradionecrosis of

temporal bone

Surgery Radiation therapy

Guidelines • Pts > 65 years of age/ poor pulmonary

function / complicating medical conditions / Di3 tumour radiation therapy

• Multicentric tumors– bilateral lower cranial nerve deficits

can be devastating– most life-threatening lesion to be

treated first

surgery

Secreting tumors

Healthy, young

patients (<65 years)

Large tumors with cranial

nerve compromise

Surgical TreatmentBASIC PRINCIPLES

• Exposure of all tumor margins• Identification/control of vital

regional anatomy• Access to all margins of ICE

Surgical technique

• Glasscock and Jackson Class I and II or Fisch C1 or C2 can be resected with extended facial recess approach

• Infratemporal fossa approach for tumors beyond petrous apex or involve cavernous sinus

• Tumors with intracranial extension may be resected with inratemporal fossa approach

• Retrosigmoid and/or suboccipital approach may be necessary for tumors with extension into posterior cranial fossa

Infratemporal fossa approach • TYPE A-JUGULAR BULB VERTICAL PETROUS CAROTID POST INFRATEMPORAL FOSSA• TYPE B-PETROUS APEX CLIVUS SUP INFRATEMPORAL FOSSA• TYPE C-NASOPHARYNX PERITUBAL SPACE ROSTRAL CLIVUS PARASELLAR AREA PTERYGOPALATINE FOSSA • TYPE D-PREAURICULAR- PETROUS APEX NASOPHARYNX PARASELLAR AREA PTERYGOPALATINE FOSSA ANTERIOR INFRATEMPORAL FOSSA

TYPE A APPROACH

TYPE B

TYPE C

PREAURICULAR APPROACH

Vagal paraganlioma

• Paraganglionic tissue associated with one of the gamglia of the vagus nerve.

• May present as palpable neck mass• Tvc paralysis or horner syndrome• May involve IX, XI, and XII

staging

Management

• Counseled about sacrifice of vagus nerve• Treatment almost same as carotid body tm• Mostly by transcervical approach • For superiorly located tm-combinde trans

mastoid and transcervical approach

Conclusion--- PPS

• Rare tumor in an complex anatomical area• Subtle clinical presentation• Radiographic imaging is important• Prestyloid vs poststyloid space• Surgery is the main treatment

Conclusion--PARAGANGLOMA

• Preop embolization and imaging aid in surgery.

• Experience in skull base surgery.• Proper counseling of patient regarding post op

complication and rehabilitation.• Rule out functional glomus.• In Future, genetic analysis may help in early

diagnosis and management.