1. Rathke's pouch remnant and pharyngeal hypophysis
The pituitary gland begins its development as a pouch which forms
in the roof of the pharynx (Rathke’s pouch). 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.

2. DOWN SYNDROME
Down 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 other
chromosomal anomalies.
The midface hypoplasia contributes to the smaller volume of both the
nasopharynx and the oropharynx.
CROUZON SYNDROME
Crouzon 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.

3. TREACHER COLLINS SYNDROME
Treacher 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 a
cleft palate. Upper airway obstruction is usually due to the
hypoplastic mandible but may be associated with a
narrowed nasopharynx. A tracheostomy is often needed.

4. Juvenile angiofibroma
Juvenile angiofibroma is an uncommon, benign and
extremely vascular tumour that arises in the tissues within
the 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.

5. PATHOGENESIS
Juvenile angiofibromas present as well-defined, lobulated
tumours that 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 that
can be spindle or stellate in shape and give rise to varying
amounts of collagen. It is this that makes some tumours
very hard or firm, while others may be relatively soft.

6. Sex-hormone receptors play some part in its
development that’s why more seen in adolescent boys.
Recent immunocytochemical techniques have been
used to show that androgen receptors are present in at
least 75 percent of tumours, these receptors being present
in both the vascular and stromal elements.
A much smaller proportion of tumours also have some
progesterone receptors. In contast, oestrogen receptors.
have not been demonstrated.
The angiogenic growth factor (vascular endothelial growth
factor (VEGF) has been found localized on both endothelial
and stromal cells.

7.  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 arm
of chromosome 11.
 It is thought that overexpression of IGFII might be
associated with a tendency to recurrence and poorer
prognosis.
 Juvenile angiofibromas have also been reported to
develop 25 times more frequently in patients with familial
adenomatous polyposis, a condition that is associated
with mutations of the adenomatous polyposis coli (APC)
gene.

8. PRESENTATION
Recurrent 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 cause proptosis, diplopia, visual loss, facial pain
and headache.
Anterior rhinoscopy is likely to confirm the presence of abundant
mucopurulent 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.

9. ASSESSMENT
In 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 necessary and can provoke
brisk haemorrhage.
The exact extent or stage of the tumour can only be
determined by a combination of CT and MR imaging .

10. Several staging systems have been proposed but
that of Fisch is 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 infratemporal
fossa/neurosurgical approaches.
Diagnostic angiography is undertaken to evaluate
the source of blood supply and as a prelude to
selective embolization.

11. 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.

12. 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.

13. Nasopharyngeal carcinoma
This endemic disease has a close association with the
EpsteinBarr virus (EBV) and is consistently (continually)
of an undifferentiated or non-keratinizing carcinoma
type.
Early diagnosis is difficult, even in high prevalence areas
where 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.

14. EPIDEMIOLOGY
In 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 that’s 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 high
prevalence of NPC.

15. The disease is approximately three times as common in men
as women this 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 2-3:1
However, in certain low-risk populations, a bimodal age
distribution with two maxima has been reported.

16. Nasopharyngeal carcinoma (WHO
Classification)
Keratinizing squamous cell ca: type I
Similar with that in rest of aerodigestive tract.
Non-keratinizing ca: type II and III
Differentiated non-keratinizing ca (type II)
Undifferentiated ca (type III)
•Type I distinct from type II : Type II/III so called
“NPC”

17. 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.

18. Genetic factors
Genetically determined susceptibility plays role in the
pathogenesis of NPC this is supported by the extremely high
incidence 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 in
high incidence areas, for example, Indians in Singapore.
The loci involved are the HLA-A, B and DR locus situated on
the short arm of chromosome 6.
Consistent deletion on the short arm of chromosomes 3
and 9 have been found on NPC biopsies, supporting the
hypothesis of an NPC tumour suppressor gene locus at
these sites.

19. EBV
 Raised 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 virus
plays 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 is
numerically very significant.
HPV: possible factor in WHO type I lesions

20. Environmental carcinogens
•Inhalants are 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: It’s observed that the fisherfolk of Hong Kong have a
higher risk of NPC but less exposure to household smoke
Salted 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 nitrosamines present in ungutted salted marine fish.
Consumption of other salted preserved foods, such as vegetables and
shrimp paste, was also found to be an independent risk factor.
These dietary carcinogens perhaps only affect susceptible
populations.

21. PATHOGENESIS
The exact steps involved in the pathogenesis of NPC are far from
clear.
•Genetically determined susceptibility undoubtedly plays a
fundamental 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 are
consistently found in both differentiated and undifferentiated types
of NPC. Within the tumour cells, the EBV DNA has the characteristic
of 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.

22. EBV infection is widespread in all parts of the world, infecting over
95 percent of 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 may
actually 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.

23. PATHOLOGY
Nasopharynge carcinoma may present itself in a variety of
ways. However, a mass in the nasopharynx is a
constant finding in almost all patients. However,
nasopharyngeal carcinoma is by far the most common,
irrespective of geography and race.

24. Nonetheless, the tumour is typically eccentric, being more
bulky on one side.
Morphologically, the tumour mass may present with:

25. 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.

26. WHO classification of tumours of the
nasopharynx.
I Epithelial tumours
A Benign
1 Papil loma
2 Pleomorphicadenoma
3 Oncocytoma
4 Basal cell adenoma
5 Ectopic pituitary a denom a
B Malignant
1 Nasopharyngeal carcinoma
2 Adenocarcinoma
3 Papillary adenocarcinoma
4 Mucoepidermoid carcinoma
5 Adenoid cystic carcinoma
6 Polymorphous low-gra de
a denocarcinoma

27. II Soft tissue tumours
A Benign
1 Angiofibroma
2 Haemangioma
3 Haemangiopericytoma
4 Neurilemmoma
5 Neurofibroma
6 Paraganglioma
B Malignant
1 Fibrosarcoma
2 Rhabdomyosarcoma
3 Angiosarcoma
4 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 phoma
2 Extramedullary plasmacytoma
3 Midline malignant reticulosis
4 Histocytic lymphoma
5 Hodgkin's disease

28. V Miscellaneous tumours
A Benign
1 Meningioma
2 Craniopharyngioma
3 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 Granulomas
4 Amyloid deposits
5 Others

29. HISTOLOGICAL CLASSIFICATION
To date, the WH0 classification is still the one most
commonly used.
It divides nasopharyngeal carcinoma into three
histological 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 II
only

30. 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 of
these 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 2
tumours, 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.

31. CLINICAL FEATURES
The commonest complaint at presentation is the
presence of an upper neck swelling .
Unilateral neck swelling is much more common although
bilateral metastases are not infrequent.
Cervical LAP is the presenting complaint in almost 50 % of
patients.
Overall, 75 % of all patients have palpable cervical LAP at
diagnosis.
30 % of patients present with nasal symptoms including
bloodstained nasal discharge, nasal obstruction, post-nasal
drip or even frank epistaxis.

32. Approximately 20 % of patients present with aural symptoms
including deafness, tinnitus and otalgia.
Retracted tympanic membrane or OME is 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.
Headache is a common complaint occurring in almost 20
percent of patients. Headache alone may not necessarily
imply locally advanced disease as it may be referred pain
when distal branches of the trigeminal nasopharynx or nose.
However, it can also be the result of bony erosion of the
skull base.

33. 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 paresis of one or more of the last cranial nerves.
Trismus, before radiotherapy, is rare and occurs only with direct
infiltration of the pterygoid muscles.
Ophthalmoplegia, when accompanied by proptosis, is indicative
of direct tumour extension to the orbit. Orbital involvement was
more frequently encountered in the pre-CT era.

34. 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 making
the diagnosis.

35. Oropharyngeal tumours
PATHOLOGY
Benign tumours
Benign tumours occur more frequently in the oral cavity than in the
oropharynx and include squamous papilloma, adenoma, fibroma,
haemangioma, leiomyoma, lipoma, lymphangioma, schwannoma,
neurofibroma and others.
The lingual thyroid refers to a mass of ectopic thyroid tissue
located 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 rare
reports 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.

36. Desmoid tumours 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 their
invasive growth patterns.
Histologically, they are of low cellularity, have a benign
appearance lacking the nuclear and cytoplasmic features of
malignancy and, clinically, they do not display any metastatic
potential. Function-preserving surgery is the primary treatment
to minimize morbidity.

37. Malignant tumours
Malignant tumours of the oropharynx may arise from any
of its constituent tissues but the vast majority of epithelial
tumours are 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 other
sites 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. There
is the possibility of more uncommon tumours such as
soft tissue sarcomas and metastases from distant sites
presenting in the oropharyngeal region.

38. 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.

39. SQUAMOUS CELL CARCINOMA
Epidemiology
Oropharyngeal squamous carcinoma is said to represent
10-15 percent of all head and neck tumours, 0.3-0.5
percent 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 % and
posterior 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.

40. Gross Findings
The 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 as
mild 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.

41. 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 and
hyperchromatic 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.

42. Aetiology
The 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- HIV may be implicated in the development or
acceleration of squamous cell carcinoma.
Patients who are HIV positive are prone to developing
Kaposi's sarcoma, lymphoma or squamous cell carcinoma.

43. 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 of
tongue.
It is associated with a high incidence of nodal
metastases and its clinical behaviour is similar to
nasopharyngeal carcinoma.

44. LYMPHOMA
Non-Hodgkin's lymphoma accounts for approximately 8
percent of oropharyngeal cancers. The tonsil and the
base of tongue are 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.

45. The majority of NHL of Waldeyer’s tonsillar 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 extranodal
malignant lymphomas, including head and neck sites
(nasopharyngeal,
tonsil, salivary glands, and others):
• less than 4% of low-grade lymphomas of Waldeyer’s
tonsillar ring are MALT lymphomas;

46. NON-HODGKIN’S LYMPHOMA (NHL) OF WALDEYER’S 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 lymphoid
tissues about the upper end of the pharynx, including the palatine
tonsils, pharyngeal tonsils (adenoids), base of tongue/
lingual tonsils.
Clinical
• Accounts for:
• approximately 20–25% 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.
•

47. 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 (80–90% of cases);
• cervical adenopathy is present in approximately 65% of
patients;
• systemic symptoms (e.g. fever, night sweats, other) not
common;
• multifocality may be present.

48. 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 Epstein–Barr virus is considered weak.
Pathology
Gross
• Often a large exophytic submucosal mass with or
without
surface ulceration.
H

49. Histology
• 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:
• Waldeyer’s ring 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 Waldeyer’s ring NHL;
• most show angiocentric features;
• uncommonly, anaplastic large cell lymphoma (ALCL)

50. 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 50
percent are adenoid cystic carcinoma but other
malignancies include mucoepidermoid carcinoma,
adenocarcinoma and malignant mixed salivary
tumours.

51. METASTATIC DISEASE PRESENTING IN THE
OROPHARYNX
Seldom 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.

52. Diagnosis
Documentation 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 tumour’s relationship to surrounding
structures.
Endoscopy in the operating room will add to the evaluation
of the tumour and biopsies are made.

53. Staging
Oropharyngeal primary tumours are staged mainly by
size, while for hypopharyngeal tumours the location and
the relation to the larynx are also important.

54. Tongue Base Tumours
Tongue 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 larynx
and 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.

55. Soft Palate and Pharyngeal Walls
Cancers of the soft palate or pharyngeal walls are treated
analogously to tonsil and tongue base tumours.
Hypopharyngeal Carcinoma
Hypopharyneal 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 tumour’s relationship
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.

56. HYPOPHARYNGEAL SQUAMOUS CELL CARCINOMA
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 recognized – the
nasopharynx, oropharynx, and hypopharynx – with no specific anatomic
barriers 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 cartilage.

57. 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 65–85% of carcinomas in this
region;
• posterior pharyngeal wall accounts for approximately 10–20% of
carcinomas in this region;
• postcricoid region accounts for approximately 5–15% 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).
•

58. Etiology linked to:
• tobacco smoking;
• excessive alcohol use;
• Plummer–Vinson 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.

59. Pathology
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 (65–75%) present with clinically positive ipsilateral
cervical lymph nodes; bilateral neck disease is uncommon.

60. • Posterior hypopharyngeal wall carcinomas:
• 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 the
pyriform 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.

61. • 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.