NASOPHARYNX

• Lies behind the nasal cavity and above the soft palate.

• diameter : length-4cms. width-4cms.

ap diameter-3cms.

Boundaries• Anterior wall:• Choanal orifice(free communication between the

nose and nasopharynx.)• Posterior margin of nasal septum.• Floor:• Upper surface of the soft palate.• Nasopharyngeal isthmus.• Posterosuperior wall:• Extends from the base of the skull from the superior

end of the posterior free edge of nasal septum to the level of upper surface of the soft palate

• Posterosuperior wall:• Extends from the base of the skull from the superior

end of the posterior free edge of nasal septum to the level of upper surface of the soft palate .

• It is formed by the anteroinferior surface of the body of sphenoid, basilar part of occipital bone – basisphenoid.

• Upper portion of posterior wall lies in front of the anterior arch of atlas.

• It consists of a collection of lymphoid tissue – nasopharyngeal tonsil.

• Fossa of rosenmuller:• 2.5cms depth in adults.• Anteriorly - ET orifice levatorpalati.• Posteriorly - mucosa covering the pharyngobasilar

fascia. -retropharyngeal space containing node of

rouviere. • Medially - nasopharynx cavity.• Laterally – mandibular nerve, tensor palati,

parapharyngeal space• Superiorly – foramen lacerum, floor of the carotid canal.• Posterolaterally – opening of carotid canal and petrous

apex posteriorly. foramen ovale and foramen spinosum-laterally.

Epithelial lining• Nasopharyngeal mucosa is thrown into folds and

crypts with serous and mucous glands in the submucosal layer.

• Surface area – 50 cmsq.• During fetal life there is gradual change from

respiratory ciliated epithelium to squamous epithelium in the posterior and lower part of nasopharynx.

• True squamous metaplasia – only in postnatal life, completed by 10 yrs.

• Most of the epithelium in adults is squamous type.• Fossa of rosenmuller – columnar epithelium.

Lymphatic drainage• Extensive submucosal lymphatic plexus.• Responsible for cervical node metastasis in nasopharyngeal

carcinoma.• First order drainage sites – retropharyngeal nodes.• Uppermost one i.e Node of rouviere is the main and constant

lateral group. lies anterior to mass of atlas, anteromedial to internal carotid artery.

• Efferent vessels drain to the uppermost deep internal jugular chain(in the retrostyloid parapharyngeal space compartment.)

• Then drain downwards Posteriorly to the accessory nerve group and Anteriorly to JD group.

• Nasopharynx is a midline structure, high rate of bilateral neck node metastasis.

ANGIOFIBROMA• Also called juvenile angiofibroma,• nasopharyngeal angiofibroma,• bleeding fibroma of adolescence,• Fibroangioma.

• Vascular swelling.• Prepubertal and adolescent males. mean age of

presentation-14 yrs.range-7 to 19yrs.• Strong tendency to bleed.• Pts have signs of delayed maturity(secondary sexual

characteristics)

• Pathophysiology:• The proposed origin of JNA is said to be from the

posterolateral wall in the roof of the nasopharynx.• Usually in the superior margin of sphenopalatine foramen

and the posterior aspect of the middle turbinate.• Foetal histology confirms presence of endothelial tissue

in this area.• Rather than invading the surrounding tissues this tumor

distorts and displaces, and pressure necrosis takes place to destroy and push through its bony confines.

• Intracranial extension-10 to 20%.

• Pathology:• Gross:• Firm, spongy, lobulated swellings, nodularity

increases with age.• Pink or white color.• Part of the tumor in the nasopharynx is pink(covered

with mucous membrane.• Part of it which escaped into the extrapharyngeal

areas is white.• Section:• Reticulated, whorled or spongy appearance.• Lacks a true capsule.• Edge is sharply demarcated

• Theories of Pathogenesis:• Ringertz (1938) – tumor arose from the periosteum

of nasopharyngeal vault.• Som and neffson – inequalities in the growth of

bones of skull base results in hypertrophy of underlying periosteum,in response to hormonal influence.

• Bensch and ewing – tumor probably arose from embryonic fibrocartilage between basiocciput and basisphenoid.

• Brunner – origin from conjoined pharyngobasilar and buccopharyngeal fascia.

• Sites of origin:• Previously – vault of the nasopharynx or choana.• Modern methods – sphenopalatine foramen.• Large tumors are bilobed dumb bell swellings

straddling the sphenopalatine foramen.• One component filling the nasopharynx and other

extending out into the pterygopalatine and infratemporal fossa.

• The central stalk occupies the sphenopalatine foramen at the upper end of the vertical plate of palate.

• It may displace the maxillary nerve upwards and sometimes optic nerve and invade orbit through the inferior orbital fissure – proptosis.

• Blood supply of the tumor:• Maxillary artery.• Ascending pharyngeal artery• Un named branches from internal carotid artery.

Signs and symptoms:• 2 cardinal symptoms1. nasal obstruction.(stasis,sepsis,hyposmia or anosmia)2. unprovoked intermittent epistaxis.(occasional show or

a life threatening bleed)• Voice – nasal intonation.• If soft palate is pushed down – plummy quality voice.• Blockage of eustachian tube – CHL and otalgia.• Headache – CRS, intracranial extensions.• Diplopia – secondary to the erosion of mass into the cranial

cavity causing pressure on optic chiasma• Failing of vision – pressure on optic nerve.

• Anterior rhinoscopy:-- abundant mucopurulent secretions.-- bowing of the septum to the uninvolved side.• Posterior rhinoscopy:-- pink or red mass filling the nasopharynx.• Gross physical signs are evident when the tumor has

involved the nose and infratemporal fossa.• Nasal bones are splayed out.• Swelling in the cheek and temple• Intraoral palpation in the area between the ascending

ramus of mandible and the side of maxilla – fullness bcoz of tumor that has crept around the back of the antrum

• Impaction of bulky mass in the infra temporal fossa results in extreme signs, such as trismus and bulging of the parotid gland.

• Proptosis is a definite sign that the orbital fissures have been penetrated.

• The classic frog face seen in patients with extensive disease is due to massive escape of the disease.

• Fisch staging classification:• Done for prognosis and therapeutic approaches

Stage I: Tumor limited to the nasal cavityStage II: Tumor extension into the pterygopalatine fossa, or maxillary, sphenoid or ethmoid sinuses.Stage IIIa: Tumor extension into the orbit or infratemporal fossa without intracranial involvement.Stage IIIb: Stage IIIa with extradural (parasellar) intracranial involvementStage IVa: Intradural without cavernous sinus, pituitary, or optic chiasma involvementStage IVb:Involvement of the cavernous sinus, pituitary, or optic chiasma

• Investigations:• Standard radiographs of pns – opacity in the nasal and

sinus areas.• Xray skull lateral view – mass in the nasopharynx.• Tomography in fronto-occipital plane –1. helpful in localizing the tumor.2. areas of bone destruction3. invasion of the sphenoid sinus.• Lateral tomogram:-- forward bulging of the posterior antral wall(Hallman

Miller sign) typical if the tumor fills pterygopalatine fossa.

• CT &MRI appearances that are confirmed by angiography.

• Invasion of sphenoid sinus, erosion of grater wing of sphenoid, extension into the pterygopalatine and infratemporal fossa is detectable.

• Selective angiography – recurrent angiofibroma.• Vascular blush in the postnasal space and adjacent

areas with contrast – characteristic of angiofibroma.(need for biopsy)

• MR angiography – to know the size and location of the feeding artery of the tumor (embolization)

• Differential diagnosis:1. Antrochoanal polyp2. Nasopharyngeal carcinoma3. Enlarged adenoids4. Rhinosporidiosis5. Inverted papillomas.

• Treatment:

• Depends mainly on the extent of the lesion.• Surgery is the preferred modality of treatment, if left

alone they expand into neighbouring cavities. for all stages of the mass up to stage IVa while radiotherapy is used for stage IVb.

• Mainly three lines of treatment are available:1. Surgery2. Irradiation3. Hormonal (purely supportive in nature)

• Hormonal therapy:• Oestrogens - induces shrinkage, collagen formation,

reduces vascularity.• Disadvantages – feminizing effects(breast size)• Nonsteroidal androgen receptor blocker, flutamide –

tumor shrinkage upto 44% was reported.• Disadvantages - breast tenderness, nausea,

gynaecomastia.• Hormones by themselves are carcinogens.

• Surgical treatment:• There are various approaches for removal of tumor.• If tumor is confined to nasopharynx with a small pedicle –

transpalatal approach.• Tumor extended out into posterior ethmoids and

infratemporal fossa – lateral rhinotomy, medial maxillectomy.• Alternative approach – midfacial soft tissue degloving.

Anterior, medial, posterior and lateral walls of maxillary antrum can be removed.

• This produces a large cavity, confluent with nasal cavity and postnasal space, gives adequate access for tumor removal and control of bleeding. extensions into the infratemporal fossa and inferior part of orbit can be removed.

• Surgical approaches to nasopharynx:• Transoral.• Transpalatal.• Endoscopic transnasal.• Transmaxillary• Transnasoantral• Maxillary swing.

Nasopharyngeal Carcinoma

Anatomy

• Anteriorly -- nasal cavity• Posteriorly -- skull base and vertebral

bodies• Inferiorly -- oropharynx and soft palate• Laterally -- – Eustachian tubes and tori– Fossa of Rosenmuller - most common location

Anatomy

• Close association with skull base foramen• Mucosa – Epithelium - tissue of origin of NPC• Stratified squamous epithelium• Pseudostratified columnar epithelium

– Salivary, Lymphoid structures

Epidemiology

• Chinese native > Chinese immigrant > North American native– Both genetic and environmental factors

• Genetic– HLA histocompatibility loci possible markers

Epidemiology

• Environmental– Viruses• EBV- well documented viral “fingerprints” in tumor

cells and also anti-EBV serologies with WHO type II and III NPC• HPV - possible factor in WHO type I lesions

– Nitrosamines - salted fish– Others - polycyclic hydrocarbons, chronic nasal

infection, poor hygiene, poor ventilation

Classification

• WHO classes– Based on light microscopy findings– All SCCA by EM

• Type I - “SCCA”– 25 % of NPC– moderate to well differentiated cells similar to

other SCCA ( keratin, intercellular bridges)

Classification

• Type II - “non-keratinizing” carcinoma– 12 % of NPC– variable differentiation of cells ( mature to

anaplastic)– minimal if any keratin production– may resemble transitional cell carcinoma of the

bladder

Classification

• Type III - “undifferentiated” carcinoma– 60 % of NPC, majority of NPC in young

patients– Difficult to differentiate from lymphoma by light

microscopy requiring special stains & markers– Diverse group• Lymphoepitheliomas, spindle cell, clear cell and

anaplastic variants

Classification

• Differences between type I and types II & III

– 5 year survival• Type I - 10% Types II, III - 50%

– Long-term risk of recurrence for types II & III– Viral associations• Type I - HPV• Types II, III - EBV

Clinical Presentation

• Often subtle initial symptoms– unilateral HL (SOM)– painless, slowly enlarging neck mass

• Larger lesions– nasal obstruction– epistaxis– cranial nerve involvement

Clinical Presentation

• Xerophthalmia - greater sup. petrosal n• Facial pain - Trigeminal n.• Diplopia - CN VI• Ophthalmoplegia - CN III, IV, and VI– cavernous sinus or superior orbital fissure

• Horner’s syndrome - cervical sympathetics• CN’s IX, X, XI, XII - extensive skull base

Clinical Presentation

• Nasopharyngeal examination– Fossa of Rosenmuller most common location– Variable appearance - exophytic, submucosal – NP may appear normal

• Regional spread– Usually ipsilateral first but bilateral not uncommon

• Distant spread - rare (<3%), lungs, liver, bones

Radiological evaluation

• Contrast CT with bone and soft tissue windows– imaging tool of choice for NPC

• MRI– soft tissue involvement, recurrences

• CXR• Chest CT, bone scans

Laboratory evaluation

• Special diagnostic tests (for types II & III)– IgA antibodies for viral capsid antigen (VCA)– IgG antibodies for early antigen (EA)

• Special prognostic test (for types II & III)– antibody-dependent cellular cytotoxicity (ADCC)

assay• higher titers indicate a better long-term prognosis

• CBC, chemistry profile, LFT’s

Staging

• Variety of systems used– Am Jt Comm for Ca Staging– International Union Against Ca– Ho System

• Unique NPC prognostic factors often not considered and similar prognosis between stages

Staging

• Neel and Taylor System– Extensive primary tumor +0.5– Sx’s present < 2 months before dx - 0.5– Seven or more sx’s +1.0– WHO type I +1.0– Lower cervical node dx +1.0– -------------------------------------------------------

• ADCC assay titer considered if available

Staging

• Stage A = < 0• Stage B = 0 to 0.99• Stage C = 1 to 1.99• Stage D = > 2

Treatment

• External beam radiation– Dose: 6500-7000 cGy– Primary, upper cervical nodes, pos. lower nodes– Consider 5000 cGy prophylactic tx of clinically

negative lower neck• Adjuvant brachytherapy– mainly for residual/recurrent disease

Treatment• External beam radiation - complications– More severe when repeat treatments required– Include

• xerostomia, tooth decay• ETD - early (SOM), later (patulous ET)• Endocrine disorders - hypopituitarism, hypothyroidism,

hypothalamic disfunction• Soft tissue fibrosis including trismus• Ophthalmologic problems• Skull base necrosis

Treatment Surgical management

• Mainly diagnostic - Biopsy– consider clinic bx if cooperative patient– must obtain large biopsy– clinically normal NP - OR for panendo and bx

• Surgical treatment– primary lesion – regional failure with local control– ETD

Treatment Surgical management

• Primary lesion – consider for residual or recurrent disease– approaches• infratemporal fossa • transparotid temporal bone approach• transmaxillary• transmandibular• transpalatal

Treatment Surgical management

• Regional disease– Neck dissection may offer improved survival

compared to repeat radiation of the neck• ETD– BMT if symptomatic prior to XRT– Post XRT• observation period if symptoms not severe• amplification may be more appropriate

Treatment

• Chemotherapy– Variety of agents– Chemotherapy + XRT - no proven long term

benefit– Mainly for palliation of distant disease

• Immunotherapy– Future treatment??– Vaccine??

Conclusion• 40% overall survival at 5 years• Complete H&P, careful otologic, neurologic,

cervical and NP exams• Three WHO types - all from NP epithelium• Types II, III - better prognosis, EBV assoc.• Treatment is primarily XRT