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Rathke's pouch remnant and pharyngeal hypophysisThe pituitary gland begins its development as a pouch which forms

in the roof of the pharynx (Rathkespouch). This tissue must

migrate to the site of the developing hypothalamus. In humans,this migration does not always occur flawlessly.

In some individuals, pituitary tissue remains in the roof of the

pharynx as the pharyngeal hypophysis.


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DOWN SYNDROMEDown syndrome is genetically defined by a nondisjunction

mutation that results in trisomy 21.

The incidence is one in 700, which is more common than all otherchromosomal anomalies.

The midface hypoplasia contributes to the smaller volume of both the

nasopharynx and the oropharynx.

CROUZON SYNDROMECrouzon syndrome is an autosomal dominant craniosynostosis.

The syndrome is characterized by midface hypoplasia with relative

mandibular prognathism with an anterior bite and class III occlusion.

The orbits are shallow and eyes may appear proptosed.

Frontal bossing is a marked feature.Airway obstruction because of the narrowed nasopharynx in the

newborn period and severe obstructive sleep apnoea may necessitate

a tracheostomy.


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TREACHER COLLINS SYNDROMETreacher Collins syndrome, which was assigned the term

mandibulofacial dysostosis by Franceschetti and Klein, is

the most common of the genetic syndromes. It is an

autosomal dominant condition. Typical features include

downsloping palpebral fissures, coloboma of the outer

one-third of the lower eyelid, with ciliary agenesis.Hypoplasia of the zygoma and short mandibular rami

contribute to the typical appearance of a small face. There

may be atresia of the external auditory canals and

ossicular deformities. One-third of patients may have acleft palate. Upper airway obstruction is usually due to the

hypoplastic mandible but may be associated with a

narrowed nasopharynx. A tracheostomy is often needed.


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Juvenile angiofibroma

Juvenile angiofibroma is an uncommon, benign and

extremely vascular tumour that arises in the tissues withinthe sphenopalatine foramen.

It accounts for less than 0.5% of head and neck neoplasms

and is the most common benign tumor of the

nasopharynx.Rarely, it is found at other sites in the nasal cavity and

paranasal sinuses.

It develops almost exclusively in adolescent males. As it

grows, the tumour extends into nasopharynx, paranasal

sinuses, pterygopalatine and infratemporal fossa.


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PATHOGENESISJuvenile angiofibromas present as well-defined, lobulated

tumoursthat are covered by nasopharyngeal mucosa.The tumour consists of proliferating, irregular vascular

channels within a fibrous stroma.

Tumour blood vessels typically lack smooth muscle and

elastic fibres, this feature contributing to its reputation for

sustained bleeding.

The stromal compartment is made up of plump cells thatcan be spindle or stellate in shape and give rise to varyingamounts of collagen. It is this that makes some tumours

very hard or firm, while others may be relatively soft.


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Overexpression of insulin-like growth factor II (IGFII)has also been found in a large number of juvenile

angiofibromas. The IGFII gene is situated on the short armof chromosome 11.

It is thought that overexpression of IGFII might be

associated with a tendency to recurrence and poorerprognosis.

Juvenile angiofibromas have also been reported to

develop 25 times more frequently in patients withfamilial

adenomatous polyposis, a condition that is associated

with mutations of the adenomatous polyposis coli (APC)

gene.


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PRESENTATIONRecurrent severe epistaxes accompanied by progressive

nasal obstruction are the classical symptoms of JNA at the time of

presentation.In most, there is a delay of at least six or seven months between the

onset of symptoms and presentation.

Other symptoms include swelling of the cheek, trismus, hearing loss

secondary to Eustachian tube obstruction, anosmia and a nasal

intonation or plummy quality to the voice.

More extensive tumour growth with invasion of the orbit and

cavernous sinus may causeproptosis, diplopia, visual loss, facial pain

and headache.

Anterior rhinoscopy is likely to confirm the presence of abundantmucopurulent secretions.

The soft palate is often displaced inferiorly by the bulk of the tumour

which can be seen clearly as a pink or reddish mass that fills the

nasopharynx.


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ASSESSMENTIn the past, the most suggestive finding was the antral or

Holman-Miller sign: anterior bowing of the posterior wall of

the maxillary sinus observed on a plain skull radiograph

(Waters view).

Nowadays, the diagnosis is based on the CT and MR

appearances that are sometimes confirmed by angiography.

A trans-nasal biopsy is not necessaryand can provokebrisk haemorrhage.

The exact extent or stage of the tumour can only bedetermined by a combination of CT and MR imaging .


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Several staging systems have been proposed but

that of Fischis the most robust and practical.

It defines clearly which tumours can be resected by

endonasal techniques and those that would be

better tackled by more open or infratemporalfossa/neurosurgical approaches.

Diagnostic angiographyis undertaken to evaluate

the source of blood supply and as a prelude toselective embolization.


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Fisch staging system of juvenile angiofibromas.1 Tumour limited to the nasopharyngeal cavity; bone

destruction negligible or limited to the sphenopalatine foramen.

2 Tumour invading the pterygopalatine fossa or the maxillary,

ethmoid or sphenoid sinus with bone destruction.

3 Tumour invading the infratemporal fossa or orbital region:

(a) without intracranial involvement(b) with intracranial extradural (parasellar) involvement.

4 Intracranial intradural tumour:

(a) without infiltration of the cavernous sinus, pituitary fossa or

optic chiasm

(b) with infiltration of the cavernous sinus, pituitary fossa or

optic chiasm.


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SURGICAL RESECTION

Until relatively recently, most small tumours were

resected either through a transpalatal approach,

lateral rhinotomy or mid-facial degloving approach.

Open approaches can be used for tumours of all

stages. Nowadays, stage Fisch I, 2 and some type 3

tumours are suitable for endoscopic resection using

one or two surgeon techniques.

There is much to be gained by endonasal endoscopic

techniques, for example, reduced intraoperative

blood loss, fewer postoperative complications and a

reduced length of hospital stay.


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Nasopharyngeal carcinoma

This endemic disease has a close association with theEpsteinBarr virus (EBV)and is consistently(continually)

of an undifferentiated or non-keratinizing carcinoma

type.

Early diagnosis is difficult, even in high prevalence areaswhere clinicians and the general public have an acute

awareness of the disease WHY?Because of the location

of the nasopharynx and the wide spectrum of

presentations.In many ways, NPC differs from other head and neck

cancers because of the wide spread of controversies.


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EPIDEMIOLOGYIn endemic areas, the rate can be as much as 50 times

higher than that in other countries.

The highest age-standardized incidence rate occurs in

southern China in Guangdong Province thats why NPC is

frequently referred to as the 'Guangdong tumour'.

Other Southeast Asian races, including Malays, Indonesians,

Thais, Vietnamese and Filipinos, as well as Eskimos (in

Canada, Alaska and Greenland)are also noted for a highprevalence of NPC.


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The disease is approximately three times as common in men

as womenthis is generally true both in endemic and non

endemic areas.

The tumour occurs at a much younger age than other

cancers. Its incidence starts to rise after the second decade

of life and slowly reaches a plateau, for both sexes, after the

fifth decade then very gradually drops with increasing age.Below the age of 50, the incidence of NPC is higher than any

other cancer.

M:F ratio 2-3:1However, in certain low-risk populations, a bimodal age

distribution with two maxima has been reported.


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Nasopharyngeal carcinoma (WHO

Classification)

Keratinizing squamous cell ca: type ISimilar with that in rest of aerodigestive tract.

Non-keratinizing ca: type II and IIIDifferentiated non-keratinizing ca (type II)Undifferentiated ca (type III)

Type I distinct from type II : Type II/III so calledNPC


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AETIOLOGY

The development of NPC is the result of a complex

interplay of:Genetic factors,

Early latent infection by EBV and its reactivation.Exposure to environmental carcinogens.The lack of a single unique characteristic that

defines a transformed NPC cell argues in favour of a

multistep hypothesis.


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Genetic factorsGenetically determined susceptibility plays role in the

pathogenesis of NPC this is supported by the extremely highincidence amongst southern Chinese and retained high

incidence in later generations of southern Chinese

emigrants who settled in areas of low incidence.

Low risk populations have a low incidence despite living inhigh incidence areas, for example, Indians in Singapore.The loci involved are the HLA-A, B and DRlocus situated on

the short arm of chromosome 6.

Consistent deletion on the short arm of chromosomes 3and 9have been found on NPC biopsies, supporting the

hypothesis of an NPC tumour suppressor gene locus at

these sites.


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EBVRaised antibodies to EBV in patients with NPC were

confirmed first.

Then the EBV genome was found in NPC cells.The discovery of EBV receptors on human pharyngeal

epithelia.

To date, circumstantial evidence has indicated that the virusplays a critical role in the pathogenesis of NPC.

Thus, although these undesirable consequences occur in

only a tiny minority of cases infected, because the virus is so

ubiquitous (being present everywhere) this minority isnumerically very significant.

HPV:possible factor in WHO type I lesions


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Environmental carcinogensInhalantsare logically implicated as a carcinogen as they come into

direct contact with the nasopharyngeal mucosa such as: dust,

household smoke, industrial fumes and tobacco smoke. However,none of these factors has been conclusively implicated in high-risk

populations.

Formaldehyde exposure:there was no association.Ingestants:Its observed that the fisherfolk of Hong Kong have a

higher risk of NPC but less exposure to household smokeSalted fish. In Hong Kong and southern China, the highest incidence

of NPC occurs in the fisherfolk, whose diet is high in salted fish and

low in vitamin-rich fresh vegetables and fruits.

Volatile nitrosaminespresent in ungutted salted marine fish.Consumption of other salted preserved foods, such as vegetables andshrimp paste, was also found to be an independent risk factor.These dietary carcinogens perhaps only affect susceptible

populations.


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PATHOGENESISThe exact steps involved in the pathogenesis of NPC are far from

clear.

Genetically determined susceptibility undoubtedly plays afundamental role, which is supported by strong epidemiological

evidence.

The part played by the EBV, although still unconfirmed, is likely to

be critical. The EBV genome and latent gene products areconsistently found in both differentiated and undifferentiated types

of NPC. Within the tumour cells, theEBV DNA has the characteristicof being homogenous and is likely to be due to clonal cellular

proliferation.A causal relationship between EBV and NPC can only be established

when an anti-virus vaccine eradicates the cancer. Thus far,

epidemiological evidence shows that an environmental

carcinogen(s) has a definite role to play.


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EBV infection is widespread in all parts of the world, infecting over

95 percentof the human population and earning it the nickname of

'Every Body's Virus'. Primary EBV infection usually occurs early in

life and is largely asymptomatic. If primary EBV infection is delayed

until adolescence, the clinical syndrome of infectious

mononucleosis may result.

The general cell-mediated immunity (CMI) of those in whom NPC

eventually develops is more likely to be impaired. Although it is still

unsure whether impaired CMI is the cause or effect of NPC, this

impairment can be demonstrated by lymphocyte stimulation assay

or by T-cell cytotoxicity. The degree of impairment of CMI mayactually affect prognosis.

IMMUNOLOGY AND SEROLOGY

The anti-EBV serological response in NPC patients results in the

production of a wide range of specific antibodies, particularly IgA

class.


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PATHOLOGYNasopharynge carcinoma may present itself in a variety of

ways. However, a mass in the nasopharynx is aconstant finding in almost all patients. However,

nasopharyngeal carcinoma is by far the most common,

irrespective of geography and race.


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Nonetheless, the tumour is typically eccentric, being more

bulky on one side.Morphologically, the tumour mass may present with:

1- more commonly as a lobulated mass of varying size

with well-defined borders and it spreads earlier

through lymphatics and is frequently accompanied by

cervical lymphadenopathy.


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2- Or , it appears to be more infiltrative with an indistinct border

and is more likely to present with locally advanced disease with

skull base erosion but without cervical lymphadenopathy.

When the disease is picked up at a very early stage the whole tumour

may still be hidden within the fossa of Rosenmuller. In very rare

cases, the tumour can be entirely submucosal without any

observable mass in the nasopharynx.

l ifi i f f h


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WHO classification of tumours of the

nasopharynx.I Epithelial tumours

A Benign1 Papil loma

2 Pleomorphicadenoma

3 Oncocytoma

4 Basal cell adenoma

5 Ectopic pituitary a denom a

B Malignant1 Nasopharyngeal carcinoma

2 Adenocarcinoma

3 Papillary adenocarcinoma

4 Mucoepidermoid carcinoma5 Adenoid cystic carcinoma

6 Polymorphous low-gra de

a denocarcinoma


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II Soft tissue tumours

A Benign

1 Angiofibroma

2 Haemangioma3 Haemangiopericytoma

4 Neurilemmoma

5 Neurofibroma

6 Paraganglioma

B Malignant

1 Fibrosarcoma

2 Rhabdomyosarcoma

3 Angiosarcoma4 Kaposi's sarcoma

5 Malignant Haemangiopericytoma

6 Malignant nerve sheath tumour

7 Synovial sarcoma

III Tumours of bone and cartilage

IV Malignant lymphomas

1 Non- Hodgkin's lym phoma2 Extramedullary plasmacytoma

3 Midline malignant reticulosis

4 Histocytic lymphoma

5 Hodgkin's disease


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V Miscellaneous tumours

A Benign

1 Meningioma

2 Craniopharyngioma3 Teratoma

B Malignant

1 Malignant melanoma

2 Chordoma

3 Malignant germ cell tumours

VI Secondary tumours

VII Unclassified tumours

VIII Tumour-like lesions

1 Cysts

2 Meningocoele/meni ngoencephalocoele

3 Granulomas4 Amyloid deposits

5 Others


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HISTOLOGICAL CLASSIFICATION

To date, the WH0 classification is still the one most

commonly used.

It divides nasopharyngeal carcinoma into threehistological subtypes on the basis of the light microscopic

appearance:

Type I Squamous cell carcinoma (keratinizing):

- well differentiated;

- moderately differentiated;

- poorly differentiated.

Type II Nonkeratinizing carcinoma.

Type III Undifferentiated carcinoma. Now type IIonly

Th WHO (1978) l ifi i


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The WHO (1978) classification

grade 1 keratinizing squamous cell carcinoma and

grade 2 nonkeratinizing squamous cell or undifferentiated carcinoma.

In places where NPC is endemic, grade 2 tumours constitute more

than 90 percent of all cases. These tumours are EBV-related as

patients with this type of tumour typically have elevated

serological titres of antiEBV antibodies. In fact, EBV-DNAs can be

detected

within the tumour cells as well as in the peripheral circulations ofthese patients.

In low incidence areas for NPC, 25 percent or more are grade 1

tumours. These tumours are not associated with EBV infection. In

general, grade 1 tumours are less aggressive than grade 2tumours, however, they are also less radiosensitive.

Overall, the prognosis for patients with grade 1 tumours is less

favourable when compared stage to stage with patients having

grade 2 tumours.


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CLINICAL FEATURES

The commonest complaint at presentation is the

presence of an upper neck swelling .Unilateralneck swelling is much more common although

bilateral metastases are not infrequent.

Cervical LAPis the presenting complaint in almost 50 % of

patients.

Overall, 75 % of all patients have palpable cervical LAPat

diagnosis.

30 %of patients present with nasal symptoms includingbloodstained nasal discharge, nasal obstruction, post-nasal

drip or even frank epistaxis.

A i t l 20 % f ti t t ith l t


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Approximately 20 %of patients present with aural symptoms

including deafness, tinnitus and otalgia.

Retracted tympanic membrane or OMEis a very common clinical

finding.The cause of ET dysfunction may be due to the mechanical effect

of the tumour or the tumour infiltrating the ET musculature.

There is a good chance (approximately 50 percent chance from

personal experience) of spontaneous resolution of effusion after

radiotherapy.

Headacheis a common complaint occurring in almost 20

percent of patients. Headache alone may not necessarily

imply locally advanced disease as it may be referred painwhen distal branches of the trigeminal nasopharynx or nose.

However, it can also be the result of bony erosion of the

skull base.


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Cranial nerve symptom(s) may be isolated or multiple. In either

case, it occurs late in the disease from the spread of the tumour

through the foramina of the base of the skull or with

parapharyngeal involvement of the last four cranial nerves.Cranial nerves V and VI are the most commonly involved among all

the cranial nerves.

Cranial nerves III-VI, when affected together, are indicative of

cavernous sinus involvement.

Horner's syndrome is rare, but if present, is typically accompanied

by paresisof one or more of the last cranial nerves.

Trismus,before radiotherapy, is rare and occurs only with directinfiltration of the pterygoid muscles.

Ophthalmoplegia, when accompanied by proptosis, is indicativeof direct tumour extension to the orbit. Orbital involvement was

more frequently encountered in the pre-CT era.


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Systemic metastasis at presentation is rare although

eventually most NPC patients die of distant failure. The

bones and lungs are the most common sites for secondary

deposits followed by the liver.

DIAGNOSIS

A good history, together with a thorough clinical examination

including endoscopy of the nasopharynx, is the basis for makingthe diagnosis.

O h l t


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Oropharyngeal tumours

PATHOLOGY

Benign tumours

Benign tumours occur more frequently in the oral cavity than in theoropharynx and include squamous papilloma, adenoma, fibroma,

haemangioma, leiomyoma, lipoma, lymphangioma, schwannoma,

neurofibroma and others.

The lingual thyroidrefers to a mass of ectopic thyroid tissuelocated in the base of the tongue in the midline. Affected

individuals have no other thyroid tissue in 70-100 percent of cases.

There is a marked female predominance. Most lingual thyroid

glands contain histologically normal tissue, but there are rarereports of carcinoma arising within the lingual thyroid.

The swelling can be treated with suppressive doses of thyroxine,

with surgery reserved for large symptomatic masses or when the

diagnosis is in doubt.


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Desmoidtumours are rare, nonmalignant, slow growing

neoplasms with the potential for locally aggressive growth

invading surrounding structures. Desmoids are sometimes

misclassified as low-grade fibrosarcomas because of theirinvasive growth patterns.

Histologically, they are of low cellularity, have a benign

appearance lacking the nuclear and cytoplasmic features ofmalignancy and, clinically, they do not display any metastatic

potential. Function-preserving surgery is the primary treatment

to minimize morbidity.


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Malignant tumoursMalignant tumours of the oropharynx may arise from any

of its constituent tissues but the vast majority of epithelial

tumoursare squamous cell carcinomas (70 percent).

There is a higher concentration of lymphoid tissue in the

oropharynx and the incidence of lymphomas (25 percent)

is, therefore, considerably higher compared with othersites in the upper aerodigestive tract.

There are also concentrations of minor salivary glands in

the soft palate, uvula and base of tongue, which

may present as a salivary malignancy 5 percent. Thereis the possibility of more uncommon tumours such as

soft tissue sarcomas and metastases from distant sites

presenting in the oropharyngeal region.


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Malignant Neoplasms of the Oropharynx About 10% to 12% of all head and neck malignancies are

oropharyngeal tumors,

On the basis of different diagnostic, therapeutic, and

outcome characteristics, the oropharynx should be

subdivided into

soft palate,tonsillar fossae,

base of tongue, and

oropharyngeal wall.

SQUAMOUS CELL CARCINOMA


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SQUAMOUS CELL CARCINOMA

Epidemiology

Oropharyngeal squamous carcinoma is said to represent

10-15 percent of all head and neck tumours, 0.3-0.5percent of all registered malignancies .

The frequency distribution of the primary site carcinoma in

the oropharynx is tonsil or faucial pillar 45 %,

posterior tongue 40% , soft palate 15% andposterior pharyngeal wall 5 %. The

condition is more common in men, with a sex ratio of

4:1, and is usually associated with the sixth and seventh

decades of life.

Patients aged less than 45 years are also susceptible to this

disease, and the prevention of tobacco and alcohol abuse

among younger patients is imperative.

Gross Findings


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Gross FindingsThe gross appearance of squamous lesions varies from subtle grayish-

white thickening of the mucosa to large ulcerated, flat, or fungating

masses with invasion of local structures. Depending on the degree of

desmoplasia and tumor necrosis, the cut surface of invasive

tumors ranges from solid and firm to cystic and friable.

Microscopic Findings

Dysplasia refers to neoplastic alterations of the surface epithelium

prior to invasion of the submucosa.These changes include abnormal cellular organization, increased

mitotic activity, and nuclear enlargement with pleomorphism.

Although terminology varies, pleomorphism

limited to the lower third of the epithelium is generally referred to asmild dysplasia (Figure 9-4), pleomorphism limited to the lower two-

thirds as moderate dysplasia (Figure 9-5), and pleomorphism involving

the full thickness as severe dysplasia/carcinoma in situ

(Figure 9-6). However, forms of severe dysplasia certainly can have less

than full-thickness atypia.


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Regardless of tumor grade, nests of infiltrating SCC tend to elicit a

prominent host fibrotic stromal reaction (desmoplasia) (Figure 9-3).

In contrast, HPV-related oropharyngeal SCC frequently adopts a

blue cell morphology, characterized by scant cytoplasm andhyperchromatic nuclei, referred to as nonkeratinizing SCC.

This type usually lacks surface involvement and has large nests with

smooth edges, little or no stromal reaction, and no (or limited)squamous maturation (Figure 9-7). Mitotic activity is brisk.

Lymphoepithelium-like oropharyngeal carcinoma and hybrid types

having both keratinizing and nonkeratinizing features are also seen.

Non-HPV-associated keratinizing SCC may also be seen in the

oropharynx but are uncommon.


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AetiologyThe main associated aetiological factors are:

1- Smoking and alcohol consumption, the effects of

which are cumulative.

2- Dietary deficiencies of vitamin A,

3- chronic irritants, poor dental hygiene, syphilis and

marijuana smoking have also been identified as

predisposing factors in upper aerodigestive tract cancers.

4- Enhanced expression of the human papilloma virus

types 2, 11, and 16 has been observed,

5- HIVmay be implicated in the development oracceleration of squamous cell carcinoma.

Patients who are HIV positive are prone to developing

Kaposi's sarcoma, lymphoma or squamous cell carcinoma.


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LYMPHOEPITHELIOMA

This type of malignant tumour is also know as an

undifferentiated carcinoma of nasopharyngeal type

and is a variant of squamous cell carcinoma.

It may be found in the tonsil and the base oftongue.

It is associated with a high incidence of nodalmetastases and its clinical behaviour is similar to

nasopharyngeal carcinoma.


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LYMPHOMANon-Hodgkin's lymphoma accounts for approximately 8

percent of oropharyngeal cancers. The tonsil and the

base of tongueare the most frequent sites.

The vast majority are of the high grade B cell type

(mostly large B cell type).

Men predominate 2:1 with the mean age at

presentation being the mid-sixties.

These lesions present with similar symptoms to the

more common squamous cell carcinoma but,

predominantly, are usually not associated with fetor.


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The majority of NHL of Waldeyerstonsillar tissues are B-

cell lymphomas, including a wide spectrum of histologic

types: most common is a large cell B-cell lymphoma;

follicular low-grade lymphomas are uncommon.

Mucosa-associated lymphoid tissue (MALT) has been

implicated as giving rise to a variety of extranodalmalignant lymphomas, including head and neck sites

(nasopharyngeal,

tonsil, salivary glands, and others):

less than 4% of low-grade lymphomas of Waldeyerstonsillar ring are MALT lymphomas;

NON HODGKINS LYMPHOMA (NHL) OF WALDEYERS TONSILLAR


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NON-HODGKINS LYMPHOMA (NHL) OF WALDEYERS TONSILLAR

RING (NASOPHARYNX, TONSILS, AND BASE OF TONGUE)

Definition: Primary malignant lymphoid cell neoplasms with the

bulk of tumor formed by a ring or group of extranodal lymphoidtissues about the upper end of the pharynx, including the palatine

tonsils, pharyngeal tonsils (adenoids), base of tongue/

lingual tonsils.

Clinical

Accounts for: approximately 2025% of NHL in Asian countries;

approximately 16% of all head and neck NHL;

approximately 50% of all primary extranodal lymphomas in the

head and neck. Majority (approximately 80%) are primary to the site of

involvement, with a minority representing secondary involvement to

an NHL at another site.

More common in men than women; occurs over a wide age


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More common in men than women; occurs over a wide age

range, but is most common in the sixth to eighth decades of life:

patients with underlying immunodeficiency condition usually

are younger. Most common sites of occurrence in descending order of

frequency are:

tonsils > nasopharynx > base of tongue.

Most common symptoms include dysphagia, odynophagia,swelling or lump in throat, decreased hearing, pain, and sore

throat:

majority of masses are unilateral (8090% of cases);

cervical adenopathy is present in approximately 65% ofpatients;

systemic symptoms (e.g. fever, night sweats, other) not

common;

multifocality may be present.

Etiology:


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Etiology: no known etiology in the majority of patients;

minority of patients have an underlying/associated

immunodeficiency condition that may predispose to NHL,including:

post-transplantation, HIV infection/AIDS.

association of NHL, especially diffuse large B-cell

lymphoma,

with EpsteinBarr virus is considered weak.

Pathology

Gross Often a large exophytic submucosal mass with or

without

surface ulceration.

H

Histology


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gy

Although any type can occur, the most common NHL is diffuse large B-cell

lymphoma (DLBCL), representing more than 50% of NHL of these sites.

Surface epithelium may be intact or ulcerated; crypt epithelium is usually intact.

Immunohistochemistry:

Waldeyersring lymphomas are predominantly but not exclusively follicular center

cell-derived, expressed by positive reactivity with B-cell markers and negative

reactivity with T-cell markers (e.g. CD3, UCHL-1).

Cytogenetics and molecular genetics:

clonal rearrangement of immunoglobulin heavy and light chain genes;

Differential diagnosis Reactive lymphoid (follicular) hyperplasia.

Infectious-related lymphoid enlargements:

infectious mononucleosis;

HIV-associated lymphoid lesions;

Nasopharyngeal non-keratinizing carcinoma, undifferentiated type. Mucosal malignant melanoma.

Rhabdomyosarcoma.

Peripheral T-cell lymphomas:

represent less than 15% of Waldeyersring NHL;

most show angiocentric features;

uncommonly, anaplastic large cell lymphoma (ALCL)

S O S


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SALIVARY GLAND TUMOURS

Minor salivary gland tissue is located in the

oropharynx and is concentrated in the soft palate,

tonsil and the posterior tongue.

Of the malignant salivary tumours, more than 50percent are adenoid cystic carcinomabut other

malignancies include mucoepidermoid carcinoma,

adenocarcinoma and malignant mixed salivarytumours.


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METASTATIC DISEASE PRESENTING IN THE

OROPHARYNXSeldom reported as a series and thus difficult to

quantify metastatic disease presenting in the oropharynx

are most likely to be primaries outside the head and

neck area - breast, lung, stomach, prostate and kidney.Malignant melanoma should always be suspected if such

a disease has been previously treated in the head and

neck region.

Di i


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DiagnosisDocumentation of a detected mass in the pharynx should

include:

Multidimensional size of the tumour

Location in the different regions of the pharynx

Mobility of the lesion

Relationship to the prevertebral fascia

Relationship to the larynx and vocal cords

CT and MRI are useful in evaluating the deep extent of

the tumour and the tumoursrelationship to surrounding

structures.Endoscopy in the operating room will add to the evaluation

of the tumour and biopsies are made.

Staging


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StagingOropharyngeal primary tumours are staged mainly by

size, while for hypopharyngeal tumours the location and

the relation to the larynx are also important.

Tongue Base Tumours


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Tongue Base TumoursTongue base tumours are particularly difficult to manage

because of the important function of the tongue base. The

tongue base is important to propel food over the larynxand provide sensation and bulk to protect the larynx.

The removal of the tongue base even without any removal

of the supraglottis can therefore cause severe aspiration. If

resection would require removal of large portions of the

tongue base, a laryngectomy must be considered

to prevent aspiration.Owing to these concerns, attempts have been made to

treat tongue base tumours primarily with chemoradiation.

Soft Palate and Pharyngeal Walls


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Soft Palate and Pharyngeal Walls

Cancers of the soft palate or pharyngeal walls are treated

analogously to tonsil and tongue base tumours.

Hypopharyngeal CarcinomaHypopharyneal squamous cell carcinomas are typically

highly infiltrative with significant submucosal spread.

The majority of hypopharyngeal cancers occur in the

pyriform sinus.

In hypopharyngeal cancer, the tumoursrelationship

to the oesophagus and larynx must be thoroughly

evaluated. At the upper extent of the tumour,

oropharyngeal involvement of the tonsil or tongue base

may be detected.

HYPOPHARYNGEAL SQUAMOUS CELL CARCINOMA


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Definition: Hypopharyngeal carcinoma involves the pyriform

sinus, posterior pharyngeal wall, and postcricoid area.

Pyriform sinus: inverted pyramid- or pear-shaped sinus composed

of anterior, medial, and lateral walls converging inferiorly

toward an apex at the level of the inferior border of the cricoid

cartilage:

superior border: at level of pharyngoepiglottic fold;

lateral wall: inner surface of thyroid cartilage and thyrohyoid

membrane;

medial wall: posterior surface of the aryepiglottic fold and the arytenoids and

cricoid cartilages.

Posterior pharyngeal wall: three levels of the pharynx are recognizedthe

nasopharynx, oropharynx, and hypopharynxwith no specific anatomicbarriers between them; tumors of the pharynx tend to be large at

presentation and to involve more than one level.

Postcricoid area: is bounded laterally by the pyriform sinus and extends

from the posterior surface of the arytenoid cartilage to the inferior surface of

the cricoid cartila e.

Clinical


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Clinical

More common in men than in women; peak incidence in the sixth

seventh decades of life:

for postcricoid carcinomas there is an equal gender predilection or a

greater occurrence in women. In descending order of occurrence, hypopharyngeal carcinomas involve

the pyriform sinus > posterior pharyngeal wall > postcricoid region:

pyriform sinus accounts for approximately 6585% of carcinomas in this

region;

posterior pharyngeal wall accounts for approximately 1020% ofcarcinomas in this region;

postcricoid region accounts for approximately 515% of carcinomas in this

region.

Symptoms include dysphagia, sore throat, sensation of a foreign body in

the throat, hoarseness, referred otalgia, hemoptysis, or a neck mass.

Hypopharyngeal carcinomas tend to remain quiescent for longer periods

and present with more advanced disease (i.e. T3 and T4).

Etiology linked to:


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gy tobacco smoking;

excessive alcohol use;

PlummerVinson syndrome, characterized by:

dysphagia due to webs, stenosis, or mucosal atrophy:

webs arise from anterior esophageal wall distal to the

cricoid cartilage;

carcinomas develop immediately proximal to the webs

and not within them;carcinomas may develop in other sites, including the

oral cavity and esophagus;

treatment with dietary supplements, particularly iron,

may result in disappearance of the webs, thereby

decreasing the incidence of carcinoma.

iron deficiency anemia;

glossitis;

cheilitis;

achlorhydria.

Pathology

G


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Gross

Tumors of all hypopharyngeal sites tend to be large at presentation:

those of the posterior hypopharyngeal wall are often more than 5 cm in

greatest dimension.

Histology

Majority are moderately to poorly differentiated, with infiltrative margins.

Spread

Pyriform sinus carcinomas:

medially to invade the lateral wall of the supraglottic larynx; laterally, with erosion of the thyroid cartilage and invasion

of the superior lobe of the thyroid gland;

superiorly into the base of the tongue;

across the postcricoid area, with involvement of the

opposite pyriform sinus; into the contiguous posterior pharyngeal wall.

The hypopharynx is rich in lymphatic spaces and many

patients (6575%) present with clinically positive ipsilateral

cervical lymph nodes; bilateral neck disease is uncommon.

Posterior hypopharyngeal wall carcinomas:


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may spread circumferentially to involve the larynx;

advanced carcinomas may extend superiorly, with involvement of the

tonsillar pillars, soft palate, and nasopharynx;

advanced carcinomas may extend inferiorly, with involvement of thepyriform sinus or cervical esophagus.

Incidence of nodal metastasis is less than that for pyriform sinus

carcinomas; however:

these tumors almost always cross the midline and bilateral cervical neck

disease may occur; lymphatic drainage is to the upper and middle jugular lymph nodes and to

the retropharyngeal lymph nodes;

retropharyngeal nodal metastases occurs in over 50% of cases.

Postcricoid carcinomas:


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Postcricoid carcinomas:

invasion of the cricoid cartilage and cricoarytenoid muscle;

circumferential growth may result in invasion through the

muscular lateral walls, with direct invasion of the thyroid

gland.

Nodal metastasis is common in hypopharyngeal carcinoma:

lymphatic draininage is to the middle and lower jugular

chains, to the paratracheal nodes, and to the retropharyngeal

lymph nodes.

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