Nasopharynx

ByDr Nourizadeh

Assistant professor of ENTMUMS

SPECIAL CONSIDERATION

• The pharyngeal recess is filled by the levator palati muscle and overlies the internal carotid artery, which courses at this point against the wall of the pharynx.

Blood Supply: • External carotid artery

• Ascending pharyngeal • Facial arteries

• Venous drainage • The pterygoid venous plexus (superiorly) • The pharyngeal plexus (inferiorly)

• Lymphatic drainage • The retropharyngeal nodes • The deep cervical lymph node chain

:Nerve supply

• The trigeminal nerve – The pharyngeal branch of the sphenopalatine ganglion

• Below passavant's ridge the nerve supply is the same as for the rest of the pharynx by the glossopharyngeal and vagus nerves.

Parapharyngeal space

Lateral pharyngeal space

Pre- Styloid

Post- Styloid

Retropharyngeal space

Retropharyngeal nodes

Oral phase

•Food is broken down and moistened to form a bolus

•Moved toward the oropharynx

•Voluntary

Pharyngeal phase

•Involuntary•Tongue base receptors•The velum is elevated to close off the

nasopharynx .•The larynx is also sealed off by elevation of the

epiglottis .•This is accompanied by a reflex adduction of the

vocal cords• Allowing the food to pass through the piriform

sinuses toward the esophagus while bypassing the larynx.

•Fromcranial nerves V3, VII, IX, X, and XII

Esophageal phase

•Begins with a primary peristaltic wave, which is reflexly initiated in response to movement of the

bolus through the pharynx (cranial nerves IX, X) .

•Secondary peristalsis is additionally triggered in the esophagus by the pressure of the bolus

against the esophageal wall

•Involuntary

Physiology Of The Nasopharynx

• Airflow– Like the nose, it is a noncollapsible structure.– Usually nasopharyngeal obstruction results in reflex use of

the oral airway. – The exception is in neonates, who are regarded as obligate

nasal breathers.

• Eustachian tube function

• Speech and swallowing

• Bacterial colonization

Symptoms:• Nasal obstruction:

– Severe nasal obstruction at birth suggests Bilateral Choanal Atresia– Onset at age 2 to 3 years is suggestive of:

• Adenoidal hypertrophy• Rhinitis

• Rhinorrhea

• Mouth breathing and snoring

• Posterior epistaxis

• Conductive hearing loss

• Hyper nasal speech or regurgitation

Physical Examination:

• Adenoid facies: (nonspecific)– Open mouth– Flat midface– Dark under the eyes– A dull appearance

• Postnasal mirror

• Fiberoptic flexible endoscopy – During speech and swallowing maneuvers gives functional information

about velopharyngeal closure

• Rigid endoscope

Radiology:

• Plain radiographs

• Computed tomography(CT)– The first choice of imaging for:

• Choanal atresia• Disease of the paranasal sinuses

• MRI

Adenoidal Hypertrophy

• Adenoidal hypertrophy is typically more common in children.• Complications:

– Chronic nasal obstruction adenoid facies– Eustachian tube dysfunction serous or recurrent otitis media– Sleep apnea – Pulmonary hypertension

• Acute infection is the most common nasopharyngeal disease.

• The most common organisms identified are Streptococcus pneumoniae, Moraxella catarrhalis, and Haemophilus influenzae.

Numerous authors have commented on the inappropriate use of antibiotics in an attempt to

treat upper respiratory infections that in fact have a viral etiology.

• Estimated that viral upper respiratory infection is the most common disease of humans with a prevalence rate of six to eight colds per 1,000 persons per day during the winter months.

Neoplasms

• The vast majority of tumors of the nasopharynx are malignant epithelial neoplasms.

• The second most common malignancy of the nasopharynx is malignant lymphoma.

• In children embryonal rhabdomyosarcoma can arise in this region.

• A basic distinction is drawn between squamous cell carcinomas and lymphoepithelial carcinomas (Schmincke tumor).

Nasopharyngeal Carcinoma• Symptoms:

– Patients may present with significant nasal symptoms including nasal obstruction, epistaxis, a sensation of sinus fullness, and headache.

– Some patients present with minimal nasal symptoms, but complain of otalgia or decreased hearing due to eustachian tube obstruction from the mass.

– A majority of the patients present with a mass in the neck, and in some patients this is the only complaint.

• Physical findings:

– Nasopharyngeal carcinomas are typically erythematous and friable. The tumor arises most frequently near the fossa of Rosenmuller.

– Orbital invasion can produce significant proptosis or hypertelorism.

– Cranial nerves may be involved at the skull base. In particular the trigeminal and

abducens nerves are at risk and their function should be examined.

• Cervical nodes are present in over 70% of patients. The nodes are usually involving the nodes at the mandibular angle.

• Any persistent middle ear effusion of long duration in an adult patient with no prior history of middle ear disease is suspicious for a tumor and should be investigated accordingly.

• EBV antibody titer should be determined (this shows an elevated IgA, contrasting with the elevated IgM/ IgG that is found in infectious mononucleosis).

Pathology

• WHO I tumors are keratinizing squamous cell carcinomas. In the United States these tumors account for approximately 25% of nasopharyngeal carcinomas. In areas of the world where nasopharyngeal carcinoma is common, such as Southern China, these tumors account for less than 5% of nasopharyngeal carcinomas. These tumors are not related to EBV infection.

• WHO II tumors are nonkeratinizing squamous cell carcinomas. These tumors histologically resemble transitional cell bladder cancer, and are also called transitional cell carcinoma. These tumors are related to EBV infection.

• WHO III tumors are undifferentiated carcinomas and include lymphoepithelioma. They account for the majority of nasopharyngeal carcinomas in the United States and worldwide. These tumors are related to EBV infection.

Diagnosis

• Open neck biopsies should be avoided unless all other diagnostic techniques are exhausted.

• Once there is a suspicion of nasopharyngeal carcinoma, the suspicious lesion should be biopsied. Suspicious cervical nodes can be aspirated to aid in the diagnostic workup.

• TREATMENT

• Radiation therapy regardless of stage

• Neck dissection is reserved for persistent or recurrent cervical disease

• WHO II and WHO III tumors are more radiosensitive than WHO I tumors.

Juvenile Angiofibroma

• Juvenile angiofibromas are:– Benign neoplasms

– Occur almost exclusively in adolescent males

– These tumors actually arise from the region of the sphenopalatine foramen

– Average age = 14 (10-18)

– Nasal obstruction and epistaxis (more than 80% )

– CT scanning is used to evaluate the extent of the tumor

– Unencapsulated and infiltrate the surrounding tissue. The major components are a fibrous stroma and intertwined vascular channels. The vessels are variable in size, lined by a single layer of endothelial cells, and lack elastic fibers in their walls.

• If there is clinical suspicion of an angiofibroma, a biopsy should not be performed due to the risk of heavy bleeding.

• The primary workup should include MRI or CT with IV contrast.

Treatment:– Surgery– Radiation therapy– Electrocoagulation– Hormonal administration

• Surgery and/or radiation therapy are the current main stays of treatment.

• Preoperative angiography with embolization (usually the maxillary artery) is recommended.

• Radiation is a viable option, but is best reserved for cases with intracranial extension.