2. Anatomy of pharynx
The pharynx is a musculomembranous tube that extends from the base of the
skull to the level of the sixth cervical vertebra.
Pharynx composed of 3 distinct areas:
Nasopharynx : The upper portion of the pharynx, the
nasopharynx, extends from the base of the skull to the upper
surface of the soft palate
Oropharynx: located between the soft palate and the superior
border of the epiglottis.
Laryngopharynx : located between the superior border of the
epiglottis and inferior border of the cricoid cartilage (C6),
Pharyngeal walls composed of superior, middle & inferior
pharyngeal constrictor muscles.
5. Histology of pharynx
The pharynx is lined by both stratified squamous epithelium and ciliated
pseudostratified epithelium with goblet cells (resp. epi.). Different regions
are lined by a different type of epithelium. Regions of the pharynx that are
likely to be roughened up by food are lined by stratified squamous
epithelium. Other regions of the pharynx are lined by ciliated
pseudostratified epithelium with goblet cells.
6. Types
Squamous cell carcinomas most head & neck cancers
Others:
Lymphoepithelioma
Spindle cell carcinoma
Undifferentiated carcinoma
Lymphoma (most often widespread non-Hodgkin's lymphoma)
7. Risk Factors
Smoking or chewing tobacco
Alcohol abuse
High doses of radiation therapy, particularly in the head or neck
region
Exposure to asbestos or certain industrial chemicals
Aging (being 65 years or older)
8. Type-Specific Risk Factors
Nasopharyngeal cancers
People of Chinese or Asian descent
Epstein-Barr virus (EBV)
Oropharyngeal cancer
Drinking maté (an herbal tea drink common in South America)
Human papillomavirus (HPV) infection
Hypopharyngeal cancer
Nutritional deficiencies
Iron deficiencies (plummer-Vinson syndrome)
Alcohol abuse
9. Esophageal web
Plummer-Vinson syndrome :rare disease
characterized by difficulty in swallowing, iron
deficiency anemia, and esophageal webs.
Pre-malignant post cricoid carcinoma.
Treatment with iron supplementation and
mechanical widening of the esophagus
10. Diagnosis
History
Depending on the location and extent of the cancer
Sore throat
A lump in the nose or back of the mouth, throat, or neck
A change of voice, or unusual hoarseness
Dysphagia
Coughing
Trouble breathing, or feeling "stuffed up"
Ear pain
Ringing in the ears
A dull pain behind the sternum
Headaches
Unexplained weight loss
11. Diagnosis
Physical examination may include visual inspection of the oral and nasal
cavities, neck, throat, and tongue using a small mirror and/or lights.
neck mass consisting of painless firm lymph node enlargement
Investigation :
1. Head, neck and chest X-rays
2. Endoscopy
3. Ultrasound
4. CT scan
5. MRI
6. PET scan (Positron Emission Tomography)
12. arterial blood supply
arterial blood supply of the pharynx include the ascending pharyngeal artery
, the ascending palatine branch of the facial artery , the descending palatine
and pharyngeal branches of the maxillary artery, and the muscular branch of
the superor thyroid artery.
the veins of the pharrynx
the veins of the pharrynx are similar in name to the arteries and drain into the
pterygoid plexus and the internal jugular veins
Innervation
pharynx innervated by nerve branches from the pharyngeal plexus supplied
by the glossopharyngeal and vagus nerves.
13. Progression
Spreads by:
Local extension and through the destruction of adjacent tissue,
with bony infiltration being a common early finding, can invade
the orbit (eye), the skull and the bones of the spinal cord.
Lymphatic invasion with spread to the cervical lymph nodes is
common at cancer diagnosis.
Haematogenous spread to distant sites such as the liver, bones,
lungs and spleen may also have occured at the time of cancer
diagnosis.
14. Nasopharyngeal tumors
Benign (non-cancerous) & malignant (cancerous).
Benign tumors
Rare
Occur in children and young adults
Include tumors or malformations of the vascular
system, such as angiofibromas and hemangiomas,
and benign tumors of the minor salivary glands that
are found within the nasopharynx.
15. Benign but locally aggressive vascular tumor that grows in the back of the
nasal cavity. It most commonly affects adolescent males. Patients usually
present with one-sided nasal obstruction and recurrent bleeding.
17. Presentation
Neck mass (most common initial symptom, 70%).
Serous otitis media from eustachian tube obstruction (second most common presentation,
50%).
Nasal obstruction.
Cranial nerve palsies (abducent nerve most common cranial nerve palsy) Villaret's syndrome*
Recurrent epistaxis.
Trismus, headache.
18. Risk Factors:
Regional distribution (Southern China, Northern Africa,
Southeast Asia, Alaska, Greenland).
Epstein-Barr Virus (EBV) most immunological finding in
nasopharyngeal cancer
Genetic predisposition (genotypes HLA-A2 and HLA-Bsin2).
Nitosamines (smoked meat and salted fish).
19. World Health Organization (WHO)
Classification
WHO Type I: Keratinizing Squamous Cell Carcinoma, squamous differentiation, not
associated with EBV, worse prognosis, less sensitive to radiation.
WHO II: Nonkeratinizing Squamous Cell Carcinoma, does not demonstrate definite
squamous differentiation, associated with EBV, better prognosis, sensitive to radiation .
WHO III: Undifferentiated (includes lymphoepitheliomas, anaplastic, and clear cell
variants): indistinct cell margins, may have lymphocytic stroma (lymphoepitheliomas),
associated with EBV, better prognosis, sensitive to radiation
20. Staging (based on the AJCC Staging)
T1: primary tumor confined to nasopharynx
T2: primary tumor extension into nasal fossa or oropharynx (without
parapharyngeal extension [T2a], with parapharyngeal extension [T2b])
T3: invasion of bony structures or paranasal sinuses
T4: invasion into intracranium, cranial nerves, infratemporal fossa, hypopharynx, or
orbit
21.
22. Diagnostic Tests
Diagnosis is made by biopsy of the nasopharyngeal mass.
Workup includes the following:
• Careful visual examination (by fiberoptic endoscopic examination or examination under anesthesia
[EUA]).
• Documentation of the size and location of the tumor and neck nodes.
• Evaluation of cranial nerve function including neuro-ophthalmological evaluation and audiological
evaluation.
• Computed tomographic (CT) scan or positron emission tomography (PET)-CT scan.
• Magnetic resonance imaging (MRI) to evaluate skull base invasion.
• Epstein-Barr virus titers.
24. Benign oropharyngeal tumor
Papilloma: usually asymptomatic, surgical excision is the treatment
of choice.(HPV)
Haemangioma: may be capillary or cavernous. Treatment is
diathermy coagulation or injection of sclerosing agents.
Cryotherapy and laser coagulation is also effective
Pleomorphic adenoma: mostly seen submucosally on the hard or
soft palate. It is potentially malignant and should be excised totally.
Mucous cyst: usually seen in vallecula. Surgical excision is the
treatment of choice in case of symptomatic cysts
Lipoma
26. Malignant oropharyngeal
tumor
Squamous cell carcinoma being by far the most common
histologic type.
The most important causative factors are prolonged
tobacco and alcohol exposure
Potential fascial spaces :
• The retropharyngeal space • the parapharyngeal space
When invasion does occur, tumors may spread into these
potential spaces.
27. Tonsil and tonsillar fossa (most common)
Base of tongue
Posterior pharyngeal wall
Common sites of malignancy in oropharynx
are:
29. Presentation
• Older than 45 years of age
• Throat discomfort.
• Odynophagia
• Otalgia*
• Trismus, dysphagia, and dysarthria may develop with deeper invasion.
• Bleeding, aspiration, airway obstruction, and weight loss (Late).
• Neck mass (most of the patients with oropharyngeal primaries present with
cervical adenopathy at the time of diagnosis)
30. Staging (AJCC)for oropharyngeal carcinoma
• TX Primary tumor cannot be assessed
• T0 No evidence of primary tumor
• Tis Carcinoma in situ
• T1 Tumor =2cm in greatest dimension
• T2 Tumor >2cm but not more than 4cm in greatest dimension
• T3 Tumor >4cm in greatest dimension or extension to lingual surface of the epiglottis
T4a Moderately advanced, local disease.Tumor invades the larynx, deep/extrinsic muscle of the
tongue, medial pterygoid, hard palate, or mandible
T4b Very advanced, local disease.Tumor invades lateral pterygoid muscle, pterygoid plates, lateral
nasopharynx, or skull base or encases the carotid artery
31. Hypopharyngeal tumor
Not common ; 0.5% of all malignancies.
Very poor prognosis
Almost all of them are SCC
Malignant types:
CA. of the piriform fossa in males
Post cricoid CA. in females
Vast majority of patients present with at least stage III
disease.
History of heavy smoking and drinking, hoarsness of voice.
Asymptomatic neck mass, dysphagia
Surgery followed by Radiation therapy
32.
33. General Stage
Stage I (T1, N0, M0)
Limited to one region
Oropharynx or hypopharynx tumour are smaller than a peanut (2 cm)
Not spread (M0) beyond its origin.
Stage II (T2, N0, M0)
Grown into another region of the pharynx or nearby soft tissues
Or may have spread into nearby lymph nodes
Not spread (M0) to distant sites.
Stage III (T3, N1, M0):
Grown beyond the site of origin
May have spread into nearby soft tissues or lymph nodes.
Stage IV: (Any T, Any N, M1)
May be any size
Spread throughout the body.
34. Treatment
Surgery
Preferred treatment for most oropharyngeal and hypopharyngeal cancers.
The cancer is considered localized
Tumor is considered surgically resectable .
Likely to obtain clean surgical margins
Radiotherapy
Postoperative to improve clinical outcomes
Higher-stage or larger tumors
Local invasion or metastasis
May be used by itself or in combination with chemotherapy in cases where
the tumor may be too large to be surgically removed
Most cases of nasopharyngeal cancer ((no role for surgery in treatment))
Useful as palliative treatment
35. Chemotherapy
Sometimes used with radiation in metastatic, unresectable
and/or recurrent tumors.
Postsurgically with radiation in late-stage or aggressive cancers.
Rarely effective by itself in pharyngeal cancer, but is instead a
valuable part of a multimodality treatment approach.
Immunotherapy
In Advanced Nasopharyngeal Cancers, because associated
with Epstein-Barr virus (EBV) infection, an immunotherapeutic
treatment was designed to target this virus. Investigators
isolated T cells from the blood of EBV-positive nasopharyngeal
cancer patients, and then modified the T cells to attack the EBV
virus.
36. Prognosis
Pharynx cancer tends to grow silently with symptoms of cancer often not
evident until the cancerous disease is quite advanced.
The early the diagnosis the better the prognosis
Involvement of lymph nodes in the region is associated with a poorer
prognosis of the cancer.
5 year survival rate is between 15-70%
However, in some cancer patients the course of pharynx cancer is more
indolent with a long survival rate even if the cancerous disease itself has
been controlled but not cured.
Smoking and alcohol worsen the survival rate.
*( syndrome of retroparotid space) combines ipsilateral paralysis of the last four cranial nerves (IX, X, XI, XII) and Horner syndrome (enophthalmos, ptosis, miosis).
Epithelia an myoepithelial encapsulated
* Sensory portions of this nerve synapse along with sensory nerves of the external auditory canal (Arnold’s nerve) leading to symptoms of referred otalgia.