Dr Nikhil S B

PARAPHARYNGEAL SPACE TUMORS

Bibliography

• Scott-Brown’s Otolaryngology, Head and Neck Surgery, 6th and 7th Edition

• Cummins Otolaryngology, Head and Neck Surgery, 4th Edition

• William W. Shockley, The Neck – Diagnosis and Surgery

• Eugene N. Myers, Cancer of the Head and Neck, 4th Edition

ANATOMY

Parapharyngeal Space

ANATOMYParapharyngeal Space

ANATOMYParapharyngeal Space

Prestyloid compartment

• Fat• Retromandibular parotid• Lymphnodes• Internal maxilary artery• Inferior alveolar nerve• Lingual nerve• Auriculotemporal nerve

Retrostyloid compartment

• Internal carotid artery• Jugular vein• Cervical Sympathetic chain• Cranial nerves IX-XII• Lymphnodes

Stylomandibular Tunnel

• Extension

• Medial vs Lateral tumors

ANATOMYParapharyngeal Space

Retropharyngeal Space – Node of Rouviere

PARAPHARYNGEAL TUMORS

Account for 0.5% of all head and neck neoplasms

Benign: 80% Malignant 20%

Direct extension, metastasis, primary tumors

TUMORS OF THE PARAPHARYNGEAL SPACE

Direct Extension

Metastasis

Primary tumors

Salivary gland tumors (40 – 50%)Neurogenic tumors (17 – 25%)Miscellaneous (20%)

COMMON TUMORS

Minor salivary gland tumors

Benign mixed tumor

Origin

Growth pattern

COMMON TUMORS

Pleomorphic adenoma

Most common origin – Deep lobe

Arises from island of salivary tissue or deep lobe of parotid

Growth pattern

Route of escape from deep lobe through stylomandibular hiatus

Extension into Infratemporal fossa

COMMON TUMORS

Malignant tumor of Parotid

Adenoid cystic Ca

Lateral extension picks off VII CN

Spl Characteristic

COMMON TUMORS

Neurogenic tumors

2nd most common tumor

3 categories – Schwannoma ( Neurilemmoma)

Neurofibroma

Ganglion Neuroma

COMMON TUMORS

Schwannoma ( Neurilemmoma)

Most common

Origin – schwann cells

Growth pattern

Features

Schwannoma ( Neurilemmoma)

COMMON TUMORS

Neurofibroma

Dual origin

Charateristic Growth patern

Ganglion Neuroma

Rare

Characteristics

COMMON TUMORS

Chemodectoma / Paraganglioma

Arise from chemoreceptor organs along carotid bifurcation; trunk of vagus; Jugular bulb

Carotid body tumors

Glomus vagale tumors

Glomus jugulare tumors

Incidence

Most common is Carotid body tumor followed by

Jugulotympanic and Vagal paraganglioma

Lack et al – 0.012 % of all tumors; 1 in 30,000 Head & Neck

tumors

Incidence

Male : Female – 2:1 (US); 1:8.3 (Mexico)

Most paraganglioma are solitary

Multiple seen in familial syndromes – MEN II A & B

Biochemistry

APUD System

Convert Dopa & Dopamine to neurotransmitters

Biochemical synthesis of catecholamine – Adrenal

Diet Tyrosine ---- L-dopa ----Dopamine

PhenylalanineEpinephrine Norepinephrine

Biochemical Activity

Functional tumors – 1 – 3 %

4 – 5 times increase in Norepinephrine presents clinically

24 hr urine collection for norepinephrine & metabolites

Routine testing for VMA & metanephrine not recommended

Physiology

Carotid sinus – stretch receptors

Carotid body – sensitive to PaO2, pH & blood flow

Carotid body – sinus complex : Baroreceptor. Type I & II

Signals ---- Herring’s nerve ---- IX ---- Medullary area of brainstem

---- Secondary signals ---- Excite Vagal centres ---- inhibit

Vasoconstrictive center

Stimulation causes parasympathetic response

Carotid Body Tumor

Origin

Growth pattern

Extension/ complication

Carotid Body Tumor

Classification – 3 stage classification (Shamblin)

Glomus vagale

• Similar to carotid body tumors• Distiguishing growth patterns• Easier excision

Glomus jugulare

• origin

• Growth patterns

Histology

Zellballen – organized nested pattern of Type I cells

2 types of cells: Chief cells & Sustentacular cells

Chief cells

Derived from neural crest & are part of APUD

Contains secretory granules (stain with silver

hematoxylin (Argentation)

Chromogranins, Synaptophysin & NSE markers are positive in these

tumors

COMMON TUMORS

Angiofibroma

Arises close to sphenopalatine foramen

Grows into the nasopharynx or into pterygopalatine fossa

Chordoma

Derived from primitive notochord

Presents as swelling in the prevertebral region behind

nasopharynx

Involvement of lower CNs

COMMON TUMORS

Meningioma

Intracranial tumors

Extends into infratemporal fossa and then to parapharyngeal space

Ameloblastoma

Maxillary

Mandibular

Horizontal ramus

Ascending ramus

OTHER COMMON TUMORS

Metastasis to the space

Closely related to – Nasopharynx – Oropharynx – Nose & PNS – BOT – Parotid

Common metastatic

SPREAD WITHIN SPACE

Extension along path of least resistance

Medial and lateral extension

Inferior and superior extension

Parapharyngeal tumors

Symptoms

Painless Swelling in neck (54%)

Palatal /Pharyngeal swelling ( 11%)

Dysphagia ( 12%)

Hoarseness of voice (7%)

Foreign body sensation

Pain ( 10%)

Otalgia

Trismus ( < 11%)

Airway obstruction

Hearing loss

Syncope

Parapharyngeal tumors

Signs

Neck swelling Fig

Palatal /Pharyngeal swelling Fig

Parotid Mass

Trismus

Vascular thrill/ bruit

Secretory otitis media

Vocal cord palsy

Tongue deviation

Shoulder weakness

Horner’s syndrome

INVESTIGATIONS

CT Scan

• Locates tumor to prestyloid vs retrostyloid

• Bone erosion due to malignancy

• Limited soft tissue detail

MRI

• Relationship of mass to adjacent structures

• Characteristic appearances of tumor types on MRI allows preoperative Dx in 90-95% of patients

MRI

MRI

MRI

MRI

MR Angiography

• Gold standard for relationship to great vessels

• Differentiate neurogenic and vascular

Vascular displacementTumors Vascular Displacement

Deep Lobe of Parotid ICA displaced Posteriorly

Minor salivary gland tumor ICA displaced Posterolaterally

Neurogenic tumor ICA displaced anteriorly

Vagal paraganglioma ICA displaced Anteromedially

Carotid body tumors Splaying of ICA and ECA

Tissue diagnosis

FNAC accuracy rate - 88 - 95%

Improved with guided FNAC

Problems in FNAC – Tumor seeding Few cells in vascular tumors False positive

Investigations

INVESTIGATIONS

Other investigations

111Indium octreotide scan MIBG Scan Tumor markers

TREATMENT

SURGICAL Transoral

Transparotid

Transcervical

Transpharyngeal with mandibulotomy

Combined trans mastoid- transcranial

CHEMOTHERAPY

RADIOTHERAPY

Transoral

• Indicated in small tumors

• Adv – direct appch

• Disadv – Limited exposure

Tumor spillage

Transparotid (Lateral) approach

A. Total Conservative Parotidectomy

TREATMENT

Transparotid (Lateral) approach

B. Conservative Lateral approach

Transparotid (Lateral) approach

B. Conservative Lateral approach

TREATMENT

C. Radical Lateral approach

TREATMENT

Transcervical approach ( Inferior approach)

Blind dissection of the tumor

Division of Medial pterygoid ms

Medial and anteromedial dissection from Sup constrictor ms

With or without mandibulotomy

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

TREATMENT

Transcervical approach

TREATMENT

Transpharyngeal with mandibilotomy approach

• Suitable for ITF and PPS tumors• Used for large PPS tumors

Transcervical-transmastoid

• Cervical incision carried postauricularly

• Mastoidectomy

• Remove mastoid tip exposing jugular fossa

• Facial nerve may need to be dissected from Fallopian canal

TREATMENT

Radiotherapy

Neoplasms PPS

NPC highly curable (3 yr survival 60 – 66%)

Vagal paraganglioma and Glomus jugulare – control by RT

Observation

Paraganliomas grow 1.0-1.5 mm per year

Mortality less than 10% per year for untreated

TREATMENT

Chemoradiation

NPC; Rhabdomyosarcoma and other sarcomas

5 FU and Cisplatin for SCC

Doxorubicin – for glandular neoplasms

PATTERNS OF FAILURE

• Recurrence of benign lesions

• Malignant transformation of benign lesions

PROGNOSIS AND SURVIVAL

• 84 % are benign

• 67 % of malignant tumors are from salivary glands

• Tumor specific 5 yr survival (97%)

• 5 yr survival of malignant tumors – 85%

Lateral neck mass

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Oropharyngeal Mass

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