The pinna (Fig. 26.1) is made of fibroelastic cartilage. The external auditory meatus has an outer cartilage portion; the inner part is formed by the tympanic bone (Fig. 26.2). It is lined by squamous epithelium and contains ceruminous glands that produce wax. There is very little subcutaneous tissue and soft tissue swelling is very painful.

Fig. 26.1 Anatomy of the pinna.

Fig. 26.2 Anatomy of the ear.

Middle ear

The vibrating tympanic membrane is conical and attached to the margin of the bony ear canal laterally and to the handle of the malleus, the first of the three ossicles, medially (Fig. 26.2). The head of the malleus is attached to the body of the incus in the space superior to the middle ear known as the attic. The long process of the incus attaches to the head of the stapes via its lenticular process. The stapes is joined to the oval window margin by the annular ligament. The middle ear is lined by simple cuboidal epithelium containing some mucus-secreting cells. The middle ear space is connected to the nasopharynx by the Eustachian tube, which maintains the middle ear at atmospheric pressure.

The inner ear

The inner ear membrane encloses a labyrinth filled by a fluid called endolymph. This is surrounded by a bony labyrinth, the otic capsule, which is filled with perilymph. The cochlea, the hearing component of the inner ear, is a tube linking the oval and round windows, coiled up like a shell. The vestibular (balance) portion of the inner ear consists of three semicircular canals, together with their vestibule, which contains the saccule and utricle, medial to the stapes footplate. The cochlear and vestibular nerves combine in the internal auditory meatus and pass medially to the brainstem. The facial nerve enters the temporal bone through the internal auditory meatus and passes laterally to the geniculate ganglion, where it turns posteriorly (the first genu). It passes through the middle ear above the oval window and turns inferiorly (the second genu) to exit at the stylomastoid foramen.

Physiology

The pinna funnels sound into the ear canal. The tympanic membrane lever mechanism, the ossicular lever mechanism and the large size of the drum relative to the stapes footplate act as an impedance-matching transformer. Vibrations in air are thus transferred to the cochlear fluids without excessive loss of energy. The cochlea converts these endolymph vibrations into electrical impulses in the auditory nerve, by stimulation of hair cells in the organ of Corti. The maximum response to high frequencies occurs in the basal turn of the cochlea. Low frequencies maximally stimulate the apex. Auditory neurons connect via the brainstem to the auditory cortex, where again different groups of cells are stimulated by nerve impulses coded for different frequencies. The hair cells in the ampullae of the semicircular canals are stimulated by angular acceleration. The saccule and utricle are stimulated by linear acceleration. Information from the labyrinths, eyes and limbs is combined within the brainstem. Connections from the vestibular nuclei pass to the cortex and the cerebellum (Fig. 26.3).

Fig. 26.3 The vestibular system.

Assessment

Clinical features

Disorders of the external or middle ear can impair sound transmission to the inner ear and cause conductive deafness. Sensorineural deafness results from lesions of the cochlea or its nerve. Deafness is often associated with a noise in the ear (tinnitus). Ear pain (otalgia) may be due to ear disease but may also be referred from other sites (Table 26.1). Ear-related disorders of balance usually cause a sensation of movement (vertigo), most often rotation. ‘Unsteadiness’ however, typically has a non-otological cause. Patients with ear disease occasionally fall to the ground but never lose consciousness.

Table 26.1 Causes of referred otalgia

Pharynx and larynx

Mouth

Temporomandibular joints (TMJ)

• TMJ dysfunction

• Arthritis

Neck

• Cervical spondylosis

• Tumour

Paranasal sinuses

• Maxillary sinusitis

Examination

The ear canal and tympanic membrane are inspected with an otoscope, a rigid telescope or a microscope. Microscopy can assist in wax or discharge removal. Tuning fork tests differentiate between conductive and sensorineural hearing loss (Rinne’s test). In health or sensorineural deafness, a tuning fork is heard better via the ear canal (air conduction) than via the mastoid process (bone conduction). When there is a conductive hearing loss, the tuning fork is heard better by bone conduction. When hearing is symmetrical, a tuning fork placed in the centre of the forehead is heard equally well in both ears (Weber’s test). If a conductive hearing loss is present in one ear, the tuning fork is heard better in the deaf ear if the loss is conductive which can be easily shown by occluding one ear and applying the fork to your own head. Conversely, in a unilateral sensorineural deafness, the sound is louder in the good ear.

Audiometry

Hearing by air conduction can be assessed by pure tone audiometry, in which sounds of known pitch and loudness are presented to each ear in turn via headphones. Bone conduction (cochlear function) can be separately tested by applying sounds to the mastoid process. A masking tone is needed if the two cochleae are to be tested separately. The difference between the air and bone conduction gives the level of conductive hearing loss (Figures 26.4 and 26.5). The patient’s ability to hear speech can be tested by presenting lists of words via headphones. The percentage correctly identified at different loudness levels allows derivation of a speech reception threshold (50% of words correct) and a discrimination score. Middle ear function (compliance) can be assessed by tympanometry. The amount of sound from a probe reflected back from the drum is measured while the pressure in the ear canal is made to vary. The compliance is maximal when the pressure in the ear canal equals the pressure in the middle ear, because when pressure is the same on both sides of the drum it is maximally mobile. Tympanometry is most often used to confirm the presence of fluid in the middle ear.

Fig. 26.4 Audiogram showing conductive deafness.

Fig. 26.5 Audiogram showing sensorineural deafness.

Temporal bone imaging

In patients with unilateral sensorineural hearing loss, MRI is used to detect an acoustic neuroma (Fig. 26.6). MRI also demonstrates the presence of normal fluid in the cochlea before attempting cochlear implantation. CT scans can be used to demonstrate temporal bone anatomy, congenital abnormalities and fractures or unusual pathology.

Fig. 26.6 Magnetic resonance imaging (MRI) of the cerebellopontine angle.

A Normal MRI scan of cerebellopontine angle. Thin arrow = IAM (internal auditory meatus). B MRI showing an acoustic neuroma. Thick arrow = lesion compressing cerebellum.

Diseases of the external auditory meatus

Diseases of the middle ear

Acute suppurative otitis media

This is a bacterial infection of the middle ear space, usually caused by Streptococcus pneumoniae or Haemophilus influenzae, most commonly occurring in young children (3 years of age and under). Children present with a combination of ear pain (otalgia), fever and malaise. On examination, dilated blood vessels are seen on the drum surface in the early stages. The drum then becomes red and begins to bulge. Perforation with discharge frequently occurs, usually followed by spontaneous healing. Antibiotic therapy remains controversial: the majority of cases resolve spontaneously in a few days (EBM 26.1). Antibiotics are useful in high risk patients (e.g. immunosuppression) as they shorten the episodes and reduce the rate of infective complications such as mastoiditis, facial palsy or meningitis.

26.1 Antibiotics for acute otitis media in children

‘Clinicians need to evaluate whether the minimal short-term benefit from longer treatment of antibiotics is worth exposing children to a longer course of antibiotics.’

Kozyrskyj et al. Short-course antibiotics for acute otitis media. Cochrane Database of Systematic Reviews 2010, Issue 9. Art. No.: CD001095. DOI: 10.1002/14651858.CD001095.pub2

For further information: www.cochrane.org

Otitis media with effusion (OME), or ‘glue ear’

In this condition, fluid accumulates in the middle ear space, usually in children. A minority of adult cases are caused by nasopharyngeal tumours and systemic disease. Childhood OME causes hearing loss and may interfere with the acquisition of language and performance at school. Virtually all cases resolve spontaneously, but this may take as long as 10 years. Initial management involves documentation of the presence of effusion and the degree of hearing loss during a period of watchful waiting. If the effusions persist, hearing may be improved by drainage of the effusion (myringotomy) and insertion of a ventilation tube (Fig. 26.8). In children, removal of the adenoids leads to more effective resolution. Spontaneous resolution may also occur in adults, but often effusions persist. Ventilation tubes can also be of value, but some cases are better managed with a hearing aid.

Fig. 26.8 Surgical treatment of otitis media with effusion.

A Myringotomy. B Grommet insertion.

Chronic suppurative otitis media

This causes aural discharge and deafness.

Tubotympanic or mucosal disease

This is characterized by the presence of a perforation of the tympanic membrane, which typically discharges. Swimming and other activities that involve water entering the ear may exacerbate the discharge. The hearing loss is worse when the ossicles are eroded, most commonly the incus long process. Discharge can be controlled by cleaning the ear and introducing eardrops. To minimize the risks of ototoxicity, drops should be used for a maximum of 2 weeks. Surgery is indicated to prevent discharge, improve hearing or allow the patient to swim. The operation to repair a perforation is called a myringoplasty. Defects of the ossicular chain can be repaired by removing the incus and repositioning it to bridge the gap between the malleus and stapes or by using a prosthesis (ossiculoplasty).

Atticoantral or squamous disease

A cholesteatoma forms as a retracted area of the drum in which keratin accumulates. The drum tissue at the periphery of the cholesteatoma produces a number of chemical mediators that stimulate osteoclast activity. Hence the cholesteatoma can erode surrounding bone and cause complications such as disruption of the ossicular chain, facial palsy and intracranial sepsis. The primary treatment goal is to eliminate the disease. Surgical treatment (mastoidectomy) is mandatory in all but the very elderly and those who are medically unfit.

Summary Box 26.1 Otitis media

• Acute otitis media is extremely common under the age of 3 years

• The child typically awakes crying at night with a painful ear. The diagnosis is confirmed by a red, inflamed bulging tympanic membrane on otoscopy

• Pain relief is important. Antibiotics should be given to prevent the development of complications

• Otitis media with effusion (glue ear) occurs transiently in many children and is manifested by temporary hearing impairment. Most cases settle spontaneously. Bilateral persistent hearing impairment may demand surgery (adenoidectomy, or insertion of a grommet)

• Chronic otitis media involves the middle ear and mastoid mucosa. There is permanent perforation of the tympanic membrane, hearing loss and a mucopurulent discharge. Inactive ears require closure of the perforated membrane (myringoplasty) and rebuilding of the ossicular chain. Ears with cholesteatoma may require surgical removal of the posterior canal wall to open the attic or mastoid cavity and so reduce the risk of meningitis, intracranial abscess and facial palsy.

Otosclerosis

This is a condition in which the stapes becomes fixed by new bone formation. It is more common in females and sometimes runs in families. It can be treated by an operation called stapedectomy, in which the stapes is replaced by a piston attached to the incus. This produces excellent hearing improvement in the majority of patients, but a minority suffer surgically-induced, permanent inner ear damage. The hearing loss can be managed with a hearing aid.

Diseases of the inner ear

Deafness

Deafness is most commonly due to changes in the cochlea. Ageing produces a gradual deterioration in hearing acuity (presbycusis). The cochlea may be damaged by chronic noise exposure, blast injuries and temporal bone fractures. Significant noise exposure may occur in heavy industry and agriculture, from playing in rock bands and shooting. Deafness may also be inherited or a manifestation of systemic disease. Some drugs, such as aminoglycosides and cytotoxic agents like cisplatinum, can damage the cochlea. Viral infections such as mumps and rubella can also cause sensorineural deafness. Unilateral hearing loss occurs in acoustic neuroma (Fig. 26.6B).

Most cases of inner ear deafness are managed with a hearing aid, but in cases of profound deafness, hearing may be restored by a cochlear implant. This consists of a series of electrodes surgically introduced into the cochlea. A speech processor converts sound into electrical energy, which stimulates the cochlear nerve.

Vertigo

In some cases, balance disorders may arise from abnormalities of the vestibular portion of the inner ear.

Benign paroxysmal positional vertigo is a very common condition in middle age and is due to debris floating in the posterior semicircular canal which stimulates the ampulla hair cells, producing vertigo. Episodes are triggered when the affected ear is down-most – as when the patient turns over in bed. Debris can be displaced therapeutically from the posterior canal by positioning the head so that it floats out of the canal into the vestibule (Epley’s particle repositioning manoeuvre). If this fails, division of the ampullary (singular) nerve or occlusion of the posterior semicircular canal is beneficial.

Vestibular neuronitis causes severe vertigo lasting for as long as several weeks. The hearing remains normal. It is due to severe temporary reduction of vestibular function in the affected ear. Patients are managed by bed rest and vestibular sedatives, such as prochlorperazine.

Abnormal fluctuations of fluid pressure within the inner ear (endolymphatic hydrops) produce a combination of fluctuating deafness, tinnitus and vertigo known as Ménière’s disease. This uncommon condition is initially treated medically, using either a vasodilator agent (e.g. betahistine) or a diuretic. If medical treatment fails, the vestibular portion of the labyrinth may be destroyed by a middle ear injection of gentamicin. Procedures of last resort are surgical destruction of the labyrinth, or section of the vestibular nerve.

Disorders of the facial nerve

Facial palsy may result from temporal bone fractures or surgical trauma. When the nerve is divided, it may be repaired by end-to-end anastomosis or a cable graft derived from a sensory nerve of the right size, such as the sural nerve. Bell’s palsy is an idiopathic (lower motor neuron) facial palsy that usually improves spontaneously. There is some evidence that it is caused by viral infection. Steroid therapy given soon after the onset is beneficial. Herpes zoster infection of the geniculate ganglion causes facial palsy, often associated with deafness and vertigo (Ramsay–Hunt syndrome). Vesicles may be seen on the palate and on the tympanic membrane. Antiviral treatment appears helpful for Ramsay–Hunt syndrome (unlike Bell’s palsy). Intracranial disease and malignant tumours in the parotid area of the neck can also cause facial palsy.

Nose

Anatomy

The nasal skeleton consists of two nasal bones superiorly and two pairs of cartilages inferiorly (Fig. 26.9). The nasal cavity is divided in two by a partition composed of cartilage anteriorly and bone posteriorly (the nasal septum). Three turbinate bones protrude from the lateral wall of the nose (Fig. 26.10). Between the inferior and middle turbinates is the middle meatus of the nose. Most of the paranasal sinuses open into this area under cover of a soft tissue flap known as the uncinate process. Obstruction of the sinus ostia in this area can cause sinus pain and may lead to sinus infection. Superior to the superior turbinate is an area of olfactory epithelium from which arise the nerve fibres of the olfactory nerve. The anterior portion of the nasal septum is called Little’s area. Here prominent veins are often found, and nose bleeds most often arise from this part of the nose.

Fig. 26.9 Anatomy of the nasal skeleton.

Fig. 26.10 Anatomy of the nasal cavity.

Physiology

The functions of the nose are to filter, warm and moisten inspired air. Olfaction is important in its own right and as an adjunct to taste.

Assessment

Clinical features

Nasal obstruction is a common symptom with a number of causes. Sneezing and rhinorrhoea are generally due to chronic rhinitis. Purulent nasal discharge and facial pain occur in sinusitis. Loss of smell may be due either to nasal blockage that prevents odours reaching the olfactory epithelium or to damage of the olfactory nerves. Smell is an important part of taste and reduced taste is therefore usually also reported by patients with anosmia.

Examination

The nasal cavity can be inspected using a nasal speculum or an otoscope. More detailed examination, particularly of the posterior part of the nose, is carried out with a rigid telescope.

Imaging

Imaging is not required if nasendoscopy is normal. Images are useful preoperatively to give the surgeon a guide as to individual variations especially in the areas of potential hazard – orbital wall, floor of the anterior cranial fossa (skull base) and to minimize the risk of complications. Computed tomography (CT) is the best means of imaging the paranasal sinuses and also gives information about the middle meatus of the nose, where the sinus ostia are situated (Fig. 26.11). The sinuses can also be visualized by magnetic resonance imaging (MRI), but the bony anatomy is not shown and mucosal disease is exaggerated.

Fig. 26.11 Coronal CT scan sinuses.

The narrow maxillary ostia and uncinate processes are seen on this cut (arrow), lateral to the middle turbinate.

Diseases of the nose

Trauma

This may result in fracture and displacement of the nasal bones. If the fracture is not reduced within 14 days, it is usually fixed and hard to mobilize. There may also be displacement and fracture of the septal cartilage and bone (deviated nasal septum, Fig. 26.12). Corrective septoplasty surgery requires a post-trauma interval of 3 months to allow for soft tissue repair prior to surgery. Bleeding into the septum causes a septal haematoma, resulting in severe nasal obstruction. This should be drained under aseptic conditions, to prevent a septal abscess and collapse of the bridge.

Fig. 26.12 Deviated nasal septum.

Chronic rhinitis

Some cases are due to allergy to aeroallergens (pollen or dust). Otherwise, it seems to be a reaction to environmental conditions such as temperature and humidity. It may be seasonal (usually summer) or perennial. Patients complain of nasal blockage that often switches from side to side, sneezing and rhinorrhoea. Most cases are best managed medically with a steroid nasal spray. In severe cases with nasal obstruction, reduction of the inferior or middle turbinates may provide relief.

Nasal polyps

Oedematous paranasal sinus mucosa extrudes through sinus ostia to produce nasal polyps. Most are multiple swellings from the ethmoid sinuses. Rarely, there is a single posterior protrusion from the maxillary sinus (antrochoanal polyp). Unilateral disease is usually defined by a prebiopsy CT (Fig. 26.13). Temporary improvement in the resulting nasal obstruction can be produced by topical or systemic steroids. As most polyps eventually recur following excision, many patients opt for periodic courses of steroid therapy, and only resort to surgery when symptoms get out of hand. Endoscopic clearance is facilitated by use of the micro- debrider (Fig. 26.14).

Fig. 26.13 Coronal CT scan showing gross unilateral (left) nasal ‘polyp’ (arrowed).

Fig. 26.14 Set-up for endoscopic sinus surgery, with the surgeon viewing the surgical field on a television monitor.

Epistaxis

Nose bleeds may be associated with a number of disease processes (Table 26.2). They are common in healthy children and young adults. Bleeding usually arises from Little’s area and can be controlled by squeezing the nose (Fig. 26.15). In the elderly, more severe bleeding from further back in the nose may occur. In these cases, a nasal pack may be required to arrest the bleeding. Bleeding may be associated with the use of non-steroidal anti-inflammatory drugs (NSAIDs) or other antithrombotic therapy in this group. Severe bleeding not controlled by a pack can be arrested by clipping either the sphenopalatine, anterior ethmoid or maxillary artery.

Table 26.2 Diseases associated with epistaxis

Bleeding disorders

• Haemophilia

• Thrombocytopenia

• Von Willebrand’s disease

• Excessive anticoagulation (e.g. with warfarin)

Systemic disease

• Liver disease

• Renal disease

• Hypertension

• Hereditary haemorrhagic telangiectasia

Fig. 26.15 Stopping epistaxis by squeezing the nose.

Summary Box 26.2 Epistaxis

• Epistaxis in young patients usually arises from a small blood vessel in Little’s area; in older individuals, it arises from an arteriosclerotic vessel located more posteriorly

• Pressure on Little’s area by compressing the anterior septum usually stops the bleeding, and topical 1 in 1000 adrenaline (epinephrine) on cotton wool may be helpful

• Bleeding more posteriorly may require balloon compression or packing

• Coagulation defects should always be excluded. Some of these will be caused by alcohol or non-steroidal analgesics

• In persistent epistaxis, it may be necessary to clip an artery e.g. the sphenopalatine.

Paranasal sinuses

Anatomy

The paranasal sinuses are air-filled cavities that open into the nasal cavity, mostly into the middle meatus of the nose. The maxillary sinuses occupy the cheeks (Fig. 26.16) and have ostia quite high in the sinus wall. The ethmoid labyrinth consists of a number of air cells lying between the orbit and the lateral wall of the nose. The frontal sinus is an ethmoid air cell that has migrated into the frontal bone, and it is connected to the nose via the frontonasal duct, which passes down to the middle meatus. The sphenoid sinus is posterior to the ethmoid labyrinth, inferior to the pituitary fossa.

Fig. 26.16 Anatomy of the paranasal sinuses.

Diseases of the paranasal sinuses

Sinusitis

Any of the sinuses may become infected, but the most commonly involved is the maxillary sinus. The site of the pain caused by sinusitis depends on which sinus it arises from. Pain arising from the maxillary sinus is felt in the cheek, that from the ethmoid labyrinth over the nasal bridge, and frontal sinus pain in the forehead. Sphenoid sinus pain is said to be maximal at the vertex. Acute sinusitis is most commonly caused by Strep. pneumoniae or Haemophilus influenzae and typically follows an upper respiratory infection. Gram-negative organisms may cause sinusitis related to a dental abscess. In some parts of the world, fungal infection is not uncommon.

Acute sinusitis is usually managed medically. Chronic sinusitis may result from failure of resolution of acute infection or may arise insidiously. Surgical treatment is frequently required and includes enlargement of the natural ostium of the maxillary sinus, often with clearance of infected ethmoid cells. Frontal and sphenoid sinusitis are much less common. Infection may spread from the sinuses, usually the ethmoid or frontal sinuses, to involve other areas such as the cranial cavity or orbit (Fig. 26.17).

Fig. 26.17 Orbital cellulitis.

Tumours

The most common malignant neoplasm found in the paranasal sinuses is squamous carcinoma, but adenocarcinomas are seen in workers in the furniture industry, and numerous rare tumour types are also recognized. The most common sites of origin are the maxillary and ethmoid sinuses. Unfortunately, the disease has often spread beyond the primary site at presentation (Fig. 26.18). These relatively uncommon tumours are managed by a combination of surgery and radiotherapy, or by local surgery and topical chemotherapy.

Fig. 26.18 Spread of sinus cancer.

A There is evidence of spread into the cheek and orbit, with displacement of the eye. B There is ulceration of the hard palate, indicating spread into the mouth.

Nasopharynx

Anatomy

The nasopharynx lies posterior to the nasal cavity and superior to the oropharynx. The skull base lies superiorly and the Eustachian tubes open into its lateral walls.

Diseases of the nasopharynx

Adenoids

The adenoids consist of B-cell predominant lymphoid tissue and in young children they occupy a significant proportion of the space within the nasopharynx. They increase in size until the age of 5 years and then become relatively smaller as the nasopharynx continues to grow. Few adults have significant amounts of residual adenoid tissue. Adenoid hypertrophy causes nasal obstruction in some children. They also have a role in the pathogenesis of childhood middle ear effusion and, increasingly in the West, sleep apnoea syndrome. Surgical removal may be indicated to improve the outcomes of glue ear treatment and in sleep apnoea.

Tumours

Carcinoma of the nasopharynx is very common in certain areas of the Far East such as South China. It is linked to the Epstein–Barr virus, male gender and there is a hereditary predisposition. Presentations include middle ear effusion, cervical lymph nodes, nasal obstruction or epistaxis. Skull base invasion may cause ophthalmoplegia. Treatment is by radiotherapy.

Male adolescents may rarely develop a benign but locally invasive angiofibroma of the nasopharynx. It presents with nasal obstruction and epistaxis and is treated by (open or transnasal endoscopic) surgical excision. A popular open approach is midfacial degloving, where the facial skin is elevated from a buccogingival sulcus incision.

Mouth

Anatomy

The ducts of the submandibular salivary glands open into the anterior floor of mouth under cover of the tongue. The roof of the mouth is formed by the hard and soft palates. Laterally are the medial aspects of the cheeks. The parotid ducts open just above the second upper molar teeth.

Diseases of the mouth

Stomatitis and gingivitis

Inflammation of the oral mucosa and gums is often associated with poor oral hygiene. It may also be a manifestation of a systemic disorder, such as anaemia. Candida is an opportunist infection that may affect the oral cavity. It is characterized by white spots on the mucous membrane. Removal of the white material causes bleeding. Infection in the floor of the mouth may develop secondary to dental sepsis (Ludwig’s angina). Pain, dysphagia, trismus and even airway obstruction may occur.

Mouth ulcers

Aphthous ulcers are the most common type. These have a punched-out appearance and are painful. They are thought to be due to a local failure of the mechanisms that protect the oral mucosa from damage. They resolve spontaneously, but this process can be speeded by the use of local treatment with steroid pellets. Oral ulceration is also seen in systemic disorders such as pemphigus and mucous membrane pemphigoid. Rarely, oral ulceration may be due to tuberculosis or syphilis.

Retention cysts

Mucous retention cysts may occur anywhere in the oral cavity. Those inferior to the tongue are called ranulas. They result from blockage of the openings into mucous and minor salivary glands. This may clear spontaneously, but otherwise excision may be required.

Leukoplakia

Leukoplakia (white patch) develops on the oral mucosa as a response to chronic irritation – for example, by a rough tooth, tobacco or alcohol (especially brown spirits) – causing hyperkeratosis (Fig. 26.19). This may progress to dysplasia and cellular atypia, thus leukoplakia is a pre-malignant condition. Removal of both the patches and the causative factors can prevent progression.

Fig. 26.19 Leukoplakia of the tongue.

Tumours

Squamous carcinoma of the tongue is the most common neoplasm seen in the oral cavity. Lesions cause induration of the tongue, usually with ulceration (Fig. 26.20). Lymphatic spread occurs to the submental nodes and thence to other deep cervical nodes. Smoking and heavy spirit drinking are predisposing factors. Small lesions can be treated by local excision or radioactive implants (iridium wires), but more extensive tumours require excision with a margin of normal tissue. This often includes excision of part of the mandible.

Fig. 26.20 Carcinoma of the tongue.

Oropharynx

Anatomy

The oropharynx lies posterior to the oral cavity between the nasopharynx superiorly and the hypopharynx and larynx inferiorly. At the junction of the mouth and oropharynx are the tonsils, which consist of lymphoid tissue. Together with the adenoids (see above) and the lingual tonsil in the base of the tongue, they form a ring of lymphoid tissue. The system is important in the development of immunity during early infancy, but subsequently can be removed without ill effect. The pharynx itself is surrounded by three constrictor muscles arranged one inside the other like a stack of bottomless beakers.

Diseases of the oropharynx

Pharyngitis

Viral infection of the pharynx is common and often follows the common cold. Symptomatic relief can be obtained from analgesics with or without decongestants. Sore throat with exudate over the tonsils is a common manifestation of infectious mononucleosis (glandular fever). This disease is due to the Epstein–Barr virus which also causes cervical adenopathy and hepatosplenomegaly. Liver function should be tested, and patients with abnormal tests advised to refrain from alcohol for a period of time. Irritation of the pharynx may be due to tobacco smoke and acid reflux.

Tonsillitis

This is due to bacterial infection of the tonsils, usually with Strep. pyogenes. Patients present with episodic sore throat associated with dysphagia, lymph node enlargement, fever and malaise. Tonsillitis must be differentiated from viral sore throats, which are not usually associated with pyrexia and often form part of a more generalized upper respiratory tract infection. Infectious mononucleosis can easily be confused with tonsillitis (EBM 26.2). Tonsillitis may be complicated by the development of a peritonsillar abscess (quinsy). This may require incision and drainage. Recurrent tonsillitis can be treated successfully by tonsillectomy (EBM 26.3).

26.2 Antibiotics for acute sore throat

‘Antibiotics should not be used to secure symptomatic relief in sore throat.

In severe cases, where the practitioner is concerned about the clinical condition of the patient, antibiotics should not be withheld. Penicillin V 500 mg 6-hourly for 10 days is the dosage used in the majority of studies.

Practitioners should be aware that infectious mononucleosis may present with severe sore throat. Ampicillin-based antibiotics should be avoided in infectious mononucleosis.

Sore throat should not be treated with antibiotics specifically to prevent development of rheumatic fever or acute glomerulonephritis.’

SIGN Guideline 117; 2010 Management of sore throat and indications for tonsillectomy.

For further information: www.sign.ac.uk

Snoring and sleep apnoea

Snoring arises because of obstruction within the pharynx during sleep or vibration of the soft palate. In some cases, it is associated with apnoeic episodes. These individuals tend

Summary Box 26.3 Tonsils and adenoids

• Adenoids are large in small children but become relatively smaller with age

• They may cause nasal obstruction and be involved in the pathogenesis of otitis media with effusion and childhood sleep apnoea

• Tonsils may require removal because of recurrent tonsillitis or peritonsillar abscess in adults and children. Children with sleep apnoea may also benefit from tonsillectomy

• Unilateral tonsillar enlargement may be due to squamous carcinoma or lymphoma.

to sleep poorly, wake unrefreshed and become drowsy during the day. If significant apnoea is confirmed by overnight monitoring, the use of nasal continuous positive airway pressure (CPAP) may be indicated. Simple snoring can be improved by weight loss and reduction of nocturnal alcohol intake. Sleep apnoea syndrome can also occur in children, in whom adenotonsillectomy will cure over 80%.

Tumours

B cell lymphomas occur mostly in adults (with a peak in those aged 50–60 years). There is a smooth enlargement of the affected tonsil. Squamous carcinoma usually presents with ulceration of the tonsil (Fig. 26.21). The traditional association with cigarette smoking is less strong, as more now seem related to prior human papilloma virus exposure. Treatment is by (chemo) radiotherapy or surgery (including transoral laser resection).

Fig. 26.21 Carcinoma of the tonsil.

Hypopharynx

Anatomy

Below the oropharynx, the aerodigestive tract divides into an air passage (larynx/trachea) and an alimentary passage (oesophagus). The entrance to the air passage is protected by a purse string mechanism formed when the mobile cartilage of the epiglottis is drawn down over the laryngeal inlet as the aryepiglottic folds shorten. Closure of the false cords forms a second sphincteric layer to protect against aspiration. Glottic closure, conversely, serves chiefly to stop air escaping from the chest, as when sustaining a long note in phonation, straining or lifting (fixing the chest volume). The entry of material into the oesophagus is controlled by the cricopharyngeus ring of muscle. Lateral to the larynx, the pharynx continues inferiorly on both sides into a blind-ended pit known as the pyriform fossa (Fig. 26.22).

Fig. 26.22 Anatomy of the pharynx and larynx.

Physiology of swallowing

Swallowing is achieved by the coordinated contraction and relaxation of muscles. It is initiated by the tongue, which pushes the bolus to the back of the mouth. A solid bolus will then gather at the tongue base, until the tongue propels it off through the pharynx when the swallow reflex fires. The pharyngeal constrictor muscles follow the tail of the bolus – in particularly ‘mopping up’ any liquid pharyngeal residue. As the laryngeal inlet closes, the larynx itself moves upwards and forwards, widening the mouth of the oesophagus as the cricopharyngeal sphincter relaxes, and coming up over the now descending bolus. The entire sequence takes half a second, at the end of which respiration, which must pause during the swallow sequence, can resume. A much slower, smooth muscle peristaltic wave then carries the bolus down the tubular oesophagus to the stomach.

Assessment

Clinical features

Obstruction of the oesophagus and disorders that interfere with the muscle activity involved in swallowing cause dysphagia. Physical obstruction causes dysphagia that is worse for solids, whereas neurological disorders cause more difficulty with liquids. Hypopharyngeal pain may be felt locally or retrosternally, or may be referred to the ear (see Table 26.1). The level of obstructive dysphagia is always below the level at which the symptom is experienced. Hence dysphagia localized by the patient in the pharynx requires an assessment down to the gastro-oesophageal junction.

Examination

The pharynx can be assessed in the clinic using a flexible fibreoptic rhinolaryngoscope. Under general anaesthesia, the pharynx and oesophagus can be directly inspected using rigid endoscopes. A fibreoptic, ultra-thin, transnasal, digital video-oesophagoscope can be used to visualize the oesophagus under topical anaesthesia.

Imaging

A barium swallow will show structural abnormalities within the pharynx and oesophagus, and also gives some information about the dynamics of swallowing. Video recording (videofluoroscopy) can be used to provide additional information about the biomechanics of the swallow, aspiration and bolus transit. CT can be used to identify spread of oesophageal lesions into surrounding tissues and to demonstrate lesions causing external compression of the oesophagus.

Diseases of the hypopharynx

Pharyngeal pouch

This is formed by mucosal herniation through the weakest part of the pharyngeal musculature, the posterior midline between the two portions of the inferior constrictor of the pharynx. The cause may be muscular incoordination – it tends to occurs in men, in older age groups. The hall mark symptom is dysphagia for solids, as the pouch tends to fill and compress the tubular oesophagus. But there may also be regurgitation of food, sometimes hours or even days after it was swallowed. In most cases, it is possible to divide the wall between the pouch and the oesophagus anterior to it. A specially designed disposable staple gun is passed transorally via an adjustable endoscope (diverticuloscope). The jaws of the gun simultaneous cut and insert two rows of lateral staples. Once the bar is divided, there is usually only a low shelf between the pouch and the oesophagus, and food no longer builds up under pressure. If the endoscopic techniques are not possible, the pouch can be excised via a neck incision.

Tumours

Squamous carcinoma may arise from the pharyngeal walls, the epiglottis, the pyriform fossa or the upper oesophagus (postcricoid region). Postcricoid carcinoma is sometimes preceded by the development of a thin membrane in the upper oesophagus, a postcricoid web. This is associated with iron deficiency anaemia, glossitis and stomatitis (Paterson–Brown–Kelly syndrome). The web itself causes some dysphagia, and treatment of the anaemia can prevent progression to tumour. Other pharyngeal tumours are associated with smoking. Hypopharyngeal tumours are treated by radiotherapy or surgery.

Larynx

Anatomy

The larynx has a cartilaginous framework. Superiorly, it is supported and protected anteriorly by the thyroid cartilage. Inferiorly lies the cricoid cartilage, which connects to the trachea (Fig. 26.23). Within the laryngeal lumen, two soft tissue folds pass from anterior to posterior. The upper folds are the ventricular bands or ‘false cords’. The lower pair are the (true) vocal cords, which are responsible for phonation. These consist of a vocal ligament covered with mucosa. The vibrating free edge of the mucosa is important in achieving glottic closure and voice quality.

Fig. 26.23 Regions of the larynx.

Physiology of voice

Voice production requires an air supply from the lungs, the presence of normally functioning vocal cords to create vibrations, and the tongue and mouth to articulate the vibrating air source into speech.

Assessment

Clinical features

Hoarseness of the voice is the cardinal symptom of laryngeal dysfunction. Patients may also complain of pain locally or referred to the ear (see Table 26.1). The voice is weak and breathy in unilateral vocal cord palsy, but rough and husky in severe laryngitis and laryngeal cancer. Patients with psychogenic dysphonia often have a squeaky voice quality.

Examination

The larynx can be inspected in the clinic using a mirror, rigid telescope or flexible fibreoptic rhinolaryngoscope. Under general anaesthesia, a better view can be obtained using a rigid endoscope and operating microscope.

Imaging

CT can be used to assess the spread of laryngeal lesions to surrounding tissues.

Diseases of the larynx

Congenital disorders

Most congenital abnormalities of the larynx are rare. The commonest is laryngomalacia, where the laryngeal inlet – epiglottis and soft tissues which join it to the arytenoid cartilages (the aryepiglottic folds) – are high, soft and tend to collapse inwards. This causes inspiratory stridor and dyspnoea, which becomes worse during upper respiratory infections. Most children grow out of the problem by the age of 2 years and do not require active intervention. In severe cases, the CO₂ laser is used to divide or debulk the aryepiglottic folds.

Laryngitis

The commonest cause of hoarseness is acute inflammation of the vocal cords after an upper respiratory tract infection. Antibiotics are of no value but steam inhalations, voice rest and frequent drinking of small volumes of fluid may be helpful. The common predisposing factors for chronic laryngitis are smoking, acid reflux and excessive voice use. Women smokers with chronic laryngitis may have a fluid build up deep to the vocal cord epithelium (Reinke’s oedema). This can be treated by surgical drainage of the submucosal space at microlaryngoscopy. Other morphological variants of chronic laryngitis include thickened red cords, or keratotic plaques (leukoplakia). In heavy voice abusers, vocal nodules at the junction of the anterior third and the posterior two-thirds of the vocal cords may develop. These may respond to speech therapy. If removal becomes necessary, patients must accept the risk of vocal cord scar and the need to undertake postoperative voice therapy to prevent recurrence.

Patients with hoarseness in the absence of a structural or movement disorder at laryngoscopy usually have functional dysphonia, which responds well in most cases to a programme of voice care and voice therapy. In many patients, the vocal cords appear normal and the problem is functional rather than structural. Speech therapy is often helpful in these cases.

Vocal cord palsy

The palsy is usually unilateral, more often on the left side, due to the intrathoracic course of the recurrent laryngeal nerve. The most commonly seen variant, left vocal cord palsy may be caused by invasion of the recurrent laryngeal nerve by a bronchial carcinoma. The right recurrent nerve does not pass down into the chest. Damage to the recurrent laryngeal nerves in the neck may occur as a result of surgery, trauma or neoplastic invasion. Unilateral palsy causes a weak breathy voice. The voice may be improved by the injection of fat, collagen or synthetic substances lateral to the vocal ligament under local or general anaesthetic. Bilateral cord palsy tends principally to cause stridor (airway obstruction). In high (vagal trunk) lesions, dysphagia may be pronounced.

Tumours

Carcinoma of the larynx is the most common single site of origin of head and neck cancer, and is almost always squamous. Over 90% of cases occur in smokers, many of whom also drink alcohol to excess. Tumours of the glottis (true vocal cords) tend to present earlier, due to the resulting hoarseness. As the glottis has very few lymphatics, regional nodes are involved late. Larger lesions may grow in the supraglottic space until they induce airway obstruction, haemoptysis or clinically apparent nodal disease. The treatment of early lesions may be by external beam radiotherapy or endolaryngeal laser resection. At least 90% of T₁ lesions of the vocal cord are cured, provided the patient gives up smoking. Early laryngeal tumours may also be treated by excision, using a laser. The outlook is less favourable in more advanced tumours. The treatment choices include more radical primary surgery or chemoradiotherapy with salvage surgery for treatment failures. Operative treatment of the more extensive lesions usually involves total removal of the larynx. Here, the trachea is brought out on to the surface of the neck as an end tracheostome. Patients can regain speech by generating a vibrating column of air in the pharynx. There are two ways of doing this: air swallowing, or valved speech through a surgically created tracheo- oesophageal puncture. Here, the patient has the advantage of lung-powered phonation. This valve diverts air from the trachea into the pharynx. Once the valve is closed, the air is expelled through the mouth where the articulators (teeth and tongue) use the airflow to generate the sounds of speech.

Summary Box 26.4 Carcinoma of the larynx

• Persistent hoarseness in smokers should be assumed to be carcinoma of the larynx until proved otherwise

• Up to 90% of T₁ glottic tumours can be cured by radiotherapy or transoral laser resection

• More extensive or recurrent disease may require removal of the larynx

• Following laryngectomy, the trachea is brought out on to the surface of the neck. Speech production is aided by a valve in a fistula between the trachea and the oesophagus.

Tracheostomy

Tracheostomy may be required to relieve acute upper airway obstruction (Table 26.3). It is carried out by creating a window in the anterior tracheal wall at the level of the second and third tracheal rings and introducing a suitable tube. When short-term airway support and the causative pathology allow, the situation is better managed by passing an endotracheal tube. Cricothyrotomy (Fig. 26.24) provides a rapid short-term solution to airway obstruction and can be carried out with makeshift equipment. Foreign bodies in the upper airway can be displaced by turning a small child upside down. In a larger individual, a ‘bear hug’ around the chest and abdomen may expel the item (Heimlich’s manoeuvre).

Table 26.3 Causes of upper airway obstruction

Children

• Inhaled foreign body

• Acute epiglottitis

• Laryngotracheobronchitis

Adults

• Inhaled foreign body

• Acute epiglottitis

• Tumour

• Laryngeal trauma

• Bilateral vocal cord palsy

Fig. 26.24 Cricothyrotomy.

Tracheostomy may also be of value to reduce the dead space in patients with respiratory disease and to facilitate longer-term artificial ventilation.

Neck

Anatomy

Knowledge of the anatomy of the neck is essential if the likely origin of neck masses is to be determined (Fig. 26.25). In the midline lie the pharynx, larynx and trachea anteriorly. The oesophagus is deep to the trachea. The thyroid gland lies anterior and lateral to the trachea, low in the neck (i.e., confusingly, well below the thyroid cartilage). Laterally, the sternomastoid muscles link the sternum and clavicles inferiorly to the mastoid process superiorly. Between them and the midline, the anterior triangles contain the carotid arteries and jugular veins, with the related vagus nerve. Along the jugular vein is a chain of deep cervical lymph nodes (Fig. 26.26). In the submental region lie the submandibular and sublingual salivary glands. The parotid salivary glands lie posterior to the angle of the mandible and anterior to the external auditory meatus (Fig. 26.27). The facial nerve runs through the parotid gland and emerges as a number of branches. The submandibular salivary gland is the second largest major salivary gland and is situated in the floor of the mouth medial to the mandible (Fig. 26.28). Its duct passes anteriorly and opens just below the tip of the tongue. The sublingual salivary gland lies in the floor of the mouth anteriorly, close to the opening of the submandibular duct. The mucosa of the mouth contains numerous small accessory salivary glands.

Fig. 26.25 Key structures the head and neck.

Fig. 26.26 Lymph node groups in the head and neck.

Fig. 26.27 Anatomy of the parotid gland.

Fig. 26.28 Anatomy of the submandibular salivary gland.

Assessment

Clinical features

Most neck masses are painless, but infection and malignant disease may cause pain. Rapid enlargement makes malignant disease more likely. Salivary gland swellings due to duct obstruction enlarge when the patient eats; there may also be a bad taste.

Examination

After inspection, assess the duct orifices and look for medial tonsil displacement, implying deep lobe parotid disease. Palpate the neck from behind to establish the site, size, shape and consistency of the swelling. Fixation to the skin or underlying structures should be established.

Imaging

CT can be used to assess most neck masses and will sometimes reveal lymph node swellings that have not been detected clinically. Cystic swellings can be differentiated from solid ones by ultrasound. Plain X-rays can be used to demonstrate salivary calculi (Fig. 26.29). Both CT and MRI are of value in assessing salivary gland swellings (Fig. 26.30). The introduction of contrast into the duct of a salivary gland (sialogram) is occasionally used to confirm the presence of a calculus or to demonstrate inflammatory changes.

Fig. 26.29 Floor of mouth X-ray showing bilateral submandibular salivary calculi (arrowed).

Fig. 26.30 MRI scan showing parotid lipoma (arrow).

Diseases of the neck

Skin and subcutaneous swellings

Sebaceous cysts occur commonly in the head and neck and have a characteristic punctum. Furuncles or boils arise as a result of infection in hair follicles. Drainage may be required. When infection spreads to involve the dermis and subcutaneous tissue, a carbuncle is produced. It may have multiple discharging sinuses and may require wide excision. Remember the possibility of underlying diabetes mellitus. Kaposi’s sarcoma occurs in patients with AIDS.

Thyroglossal cyst

The thyroid gland begins its embryological development in the tongue base. As it descends into the neck, it remains attached to the tongue by the thyroglossal duct. This duct should completely atrophy, otherwise a thyroglossal cyst may develop. This is a midline swelling usually situated just above the upper border of the thyroid cartilage. It moves on swallowing or tongue protrusion and can become infected. Occasionally, the thyroid gland fails to migrate as far as the lower neck. Thyroglossal cysts may be differentiated from aberrant thyroid tissue by an ultrasound scan – although the requirement for this appears more medicolegal than clinical. Treatment is by surgical excision. The centre of the hyoid bone and the persistent thyroglossal duct in continuity with a cuff of tongue base should also be excised with the cyst to reduce the recurrence rate (up to 10%).

Branchial cyst and fistula

Swellings lying laterally in the upper neck may be branchial cysts. They are thought to be remnants of the second and third branchial arches yet often present in young adults. The cysts contain opaque fluid with cholesterol crystals. Lymphoid tissue is found in their walls. They may become infected and usually require excision. Branchial fistulae may occur between the skin surface, low in the neck, and the tonsil or lower pharynx internally. Infection often occurs and excision is usually required.

Other cystic swellings

Cystic hygroma is a rare, benign lymphangioma of the neck, which usually presents in early life. Complete excision is difficult, leading to frequent recurrence. Dermoid cysts may also occur in the upper neck, usually in the midline or submandibular area, in younger children. They contain skin appendages unlike sebaceous cysts. Laryngocoeles occur as a result of herniation of laryngeal mucosa laterally into the neck. They distend with air during the Valsalva manoeuvre and may become infected. Excision is usually required.

Summary Box 26.5 Lymphadenopathy

• Nodes become palpable when their diameter exceeds 1 cm, but impalpable nodes may contain tumour

• Tender nodes are usually inflammatory, whereas non-tender nodes may be malignant

• Painless neck nodes in patients over 45 years of age are often due to metastases from carcinoma. In most cases, the primary is within the head and neck. Such nodes must not be biopsied in the first instance; a thorough search for a primary lesion is the key to diagnosis

• Fine-needle aspiration cytology can be diagnostic for head and neck tumours or lymphoma

• CT defines the extent of the lymphadenopathy in cancer patients

• In lymphoma:

° the nodes are often bilaterally enlarged, rubbery, firm and discrete

° there may be is underlying immunosuppression

° extranodal disease suggests non-Hodgkin’s lymphoma

° excision biopsy is diagnostic

° bone marrow examination and CT are used in staging.

Lymph node swellings

Lymph nodes may become enlarged in response to infection in their area of drainage. Primary neoplasms (lymphomas) and secondary deposits, usually from squamous carcinomas of the head and neck must be considered among the wide differential (Table 26.4). Careful examination of the upper aerodigestive tract is therefore mandatory in assessing an undiagnosed neck node. Direct examination of the oral mucosa is followed by transnasal endoscopic examination of the nose, nasopharynx, hypopharynx, larynx and, increasingly, the oesophagus in centres offering transnasal oesophagoscopy. Supplementary palpation of the tonsils and tongue may reveal an occult tumour. If clinical findings are unhelpful the next step depends on the level of suspicion that there is a squamous cancer. PET CT scanning of the neck, fine needle aspiration cytology and rigid endoscopy under general anaesthetic with ipsilateral diagnostic tonsillectomy should all be considered. As a last resort, it may be necessary to excise the swelling for histological examination. However, small mobile lymph node swellings can be observed especially if ultrasound reveals a well preserved length to transverse ratio, i.e. a normal, oval shape. Tumour infiltrated nodes are more typically spherical.

Table 26.4 Causes of lymphadenopathy

Infective
Bacterial

• Pyogenic infection in drainage area (e.g. streptococcal tonsillitis)

• Tuberculosis

• Brucellosis

Viral

• Infectious mononucleosis

• Cytomegalovirus

• Human immunodeficiency virus (HIV)

Protozoal

• Toxoplasmosis

Neoplasms

• Lymphoma

• Metastatic squamous carcinoma

• Other metastatic tumours

Systemic disease

• Collagen diseases

• Sarcoidosis

• Amyloidosis

Salivary gland disease

Submandibular salivary gland swelling is most often due to obstruction of the duct (by a stone or inflammation). Most submandibular calculi are radio-opaque. They sometimes pass spontaneously. Those in the main duct may be removed by opening the duct, endoscopy or basket retrieval. Those within the substance of the gland usually require gland excision. Inflammatory changes can occur in the absence of stone and are confirmed by ultrasound or sialography. Chronic sialadenitis may also be an indication for removal of the submandibular gland. By contrast, most swellings of the parotid gland are (benign) tumours. Since total removal of the parotid gland would be required to treat inflammation, this should thus be avoided if possible due to the risk of damage to the facial nerve.

Salivary gland tumours

Many different tumours arise in the salivary glands. Commonest are the pleomorphic adenoma (mixed salivary tumour, Fig. 26.31) and the adenolymphoma (Warthin’s tumour). Malignant tumours and others of variable behaviour also occur (Table 26.5). Benign parotid tumours are excised with a cuff of normal tissue (superficial parotidectomy). Care must be taken to avoid damage to the facial nerve, which runs through the gland between the deep and superficial lobes. Submandibular gland tumours are treated by excision of the gland. Malignant tumours are treated by more radical surgery, with or without radiotherapy.