CHAPTER XXVI

THE NECK

Surgical Anatomy--Malformations: _Cervical auricles_; _Thyreo-glossal cysts and fistulae_; _Lateral fistula_--Cervical ribs--Wry-neck: _Varieties_; _Cicatricial contraction_--Injuries: _Contusions_--_Fractures of hyoid, larynx, etc._: _Cut-throat_--Infective conditions: _Diffuse cellulitis_; _Actinomycosis_; _Boils and Carbuncles_--Tumours: _Cystic_: _Branchial cysts_; _Cystic lymphangioma_; _Blood cysts_; _Bursal cysts_--_Solid_: _Lipoma_; _Fibroma_; _Osteoma_; _Sarcoma_; _Carcinoma_--The thymus gland--The carotid gland.

#Surgical Anatomy.#--In the middle line the following structures may be recognised on palpation: (1) the _hyoid bone_, lying below and behind the body of the lower jaw, on a level with the fourth cervical vertebra; (2) the _hyo-thyreoid membrane_, behind which lies the base of the epiglottis and the upper opening of the larynx; (3) the _thyreoid cartilage_, to the angle of which the vocal cords are attached about its middle; (4) the _crico-thyreoid_ membrane, across which run transversely the crico-thyreoid branches of the superior thyreoid arteries; (5) the _cricoid cartilage_, one of the most important landmarks in the neck. It lies opposite the disc between the fifth and sixth cervical vertebrae, and at this level the common carotid artery may be compressed against the _carotid tubercle_ on the transverse process of the sixth cervical vertebra. The cricoid also marks the junction of the larynx with the trachea, and of the pharynx with the oesophagus; at this point there is a constriction in the food passage, and foreign bodies are frequently impacted here. At the level of the cricoid cartilage the omo-hyoid crosses the carotid artery--a point of importance in connection with ligation of that vessel. The middle cervical ganglion of the sympathetic lies opposite the level of the cricoid. (6) Seven or eight rings of the _trachea_ lie above the level of the sternum, but they cannot be palpated individually. The _isthmus_ of the thyreoid gland covers the second, third, and fourth tracheal rings. As the trachea passes down the neck, it gradually recedes from the surface, till at the level of the sternum it lies about an inch and a half from the skin. The _thyreoidea ima_ artery--an inconstant branch of the anonyma (innominate) or of the aorta--runs in front of the trachea as far up as the thyreoid isthmus. The inferior thyreoid plexus of veins also lies in front of the trachea. In the superficial fascia, cross branches between the anterior jugular veins cross the middle line.

In children under two years of age the _thymus gland_ may extend for some distance into the neck in front of the trachea and carotid vessels, under cover of the depressors of the hyoid bone.

_Cervical Fascia._--This fascia completely envelops the neck, and from its deep aspect two strong processes--the prevertebral and pretracheal layers--pass transversely across the neck, dividing it into three main compartments. The posterior or _vertebral compartment_ contains the muscles of the back of the neck, the vertebral column and its contents, and the prevertebral muscles. This compartment is limited above by the base of the skull, and below is continued into the posterior mediastinum. The middle or _visceral compartment_ contains the pharynx and oesophagus, the larynx and trachea with the thyreoid gland, and the carotid sheath and its contents. These different structures derive their special fascial coverings from the processes that bound this compartment. The middle compartment extends to the base of the skull and passes into the anterior mediastinum as far as the pericardium. The connective tissue space around the subclavian vessels is continued into the axilla. The anterior or _muscular compartment_ contains the sterno-mastoid muscle and the depressor muscles of the hyoid bone. It extends upwards as far as the hyoid bone and base of the mandible, and downwards as far as the sternum and clavicle. The arrangement and limits of the different layers of the cervical fascia explain the course taken by inflammatory products and by new growths in the neck.

#Malformations of the Neck.#--Various congenital deformities result from interference with the developmental processes which take place in and around the fore-gut. These malformations are associated chiefly with imperfect development of the visceral or branchial arches and clefts, or of the hypoblastic diverticula from which the thyreoid and thymus glands are formed.

The term _cervical auricles_ is applied to small outgrowths, composed of skin, connective tissue, and yellow elastic cartilage, found usually along the anterior border of the sterno-mastoid. These appendages are usually unilateral, and are derived from the second visceral arch. Sometimes they are situated near the orifice of a lateral fistula. When, on account of their size, or their situation on an exposed part of the neck, they give rise to disfigurement, they should be removed.

_Thyreo-glossal Cysts and Fistulae._--The thyreo-glossal _cyst_ is developed in relation to the thyreo-glossal tract of His, which in early embryonic life extends from the foramen caecum at the base of the tongue to the isthmus of the thyreoid. Those that form in the upper part of the tract, in relation to the base of the tongue, have already been described (p. 538). Those arising from the lower part form a swelling in the middle line of the neck, usually above, but sometimes below the hyoid bone. They have to be diagnosed from other forms of cyst occurring in the middle line of the neck--sebaceous and dermoid cysts--and when giving rise to disfigurement they should be excised.

Such a cyst may rupture on the surface, usually as a result of superadded infection, and give rise to a _thyreo-glossal_ or _median fistula of the neck_. As a rule the external opening of the fistula is above the hyoid bone, only the upper part of the duct having remained pervious. When the whole length of the duct has persisted, the fistula extends from the skin to the foramen caecum, passing usually in front of, but sometimes through the substance of, the hyoid bone. Occasionally the fistula only extends as high as the hyoid.

The part of the tract near the tongue is lined by squamous epithelium; the lower part by columnar epithelium, which, below the level of the hyoid, is usually ciliated. Lymphoid tissue and mucous glands are found in its wall.

The _treatment_ consists in excising the duct and the connections, and it is usually necessary to resect the central portion of the hyoid bone to ensure complete removal.

The _lateral fistula of the neck_--formerly described as a branchial fistula--according to Weglowski, usually takes origin from the remains of the hypoblastic diverticulum, which arises from the pharyngeal part of the third visceral cleft and extends downwards to form the thymus gland. The internal opening is situated in the lateral wall of the pharynx in the region of the posterior palatine arch close to the tonsil, and the fistula passes out above the hypoglossal nerve, and runs downwards and laterally between the carotids and along the medial border of the sterno-mastoid muscle. When the fistula is complete, the external opening is situated a short distance above the sterno-clavicular joint. As the lower part of the thymus canal most often persists, an incomplete external fistula is the form most frequently met with. It is lined with ciliated columnar epithelium.

The fistula may be present at birth, or may result from the rupture of a cystic swelling, which has become infected. Clear viscous fluid exudes from it, and, when the fistula is complete and the lumen sufficiently wide, particles of food may escape. As the track is tortuous, it is seldom possible to pass a probe along it, but its extent and course may be recognised by injecting an emulsion of bismuth and taking an X-ray photograph.

The _treatment_ consists in excising the fistula in its whole length, but, owing to its long and tortuous course, and its relations to important structures, the operation is a tedious and difficult one. Less radical measures, such as scraping with the sharp spoon, cauterising, or packing, are seldom successful.

#Cervical Ribs.#--Supernumerary ribs are not infrequently met with in connection with the seventh cervical vertebra, and in the majority of cases the condition is bilateral. The extra rib may be thin and pointed, and project straight out from the transverse process terminating in a free end, in which case, as it passes above the subclavian artery and the brachial plexus, it gives rise to no trouble. In other cases it arches downwards and forwards, and is attached by dense fibrous tissue to the first thoracic rib about the level of the scalene tubercle, or to the sternum by cartilage like an ordinary rib. When it encroaches upon the posterior triangle the scalene muscles are attached to it, and the subclavian artery and the lower trunk and medial cord of the brachial plexus pass over it in a groove behind the scalenus anterior. The pleura may reach as high as the medial border of the rib.

_Clinical Features._--The condition, which is more common in women than in men, is seldom recognised before the age of twenty, and is often discovered accidentally, for example after some emaciating illness, or by a tight collar causing pain. The diagnosis is established by the X-rays.

When symptoms arise, they may be referable either to pressure on the artery or on the nerve roots. When the subclavian artery is displaced upwards it may be recognisable as a prominent pulsatile swelling, and as the part of the vessel distal to the rib is sometimes dilated and yields a systolic bruit, it may simulate an aneurysm (Sir William Turner). The pulse beyond is weakened while the arm hangs by the side, but may be restored by raising the hand above the head. Gangrene of the tips of the fingers has been observed in rare instances, but it is probably nervous rather than vascular in origin.

Symptoms referable to pressure on the nerve roots usually affect the right arm, and may be either neuralgic or paralytic in character (Wm. Thorburn). In the neuralgic group there is tingling pain, a feeling of numbness, and sensations of cold in the limb, most marked along the ulnar border of the forearm; the arm is weak, and susceptible to cold. This condition may be mistaken for brachial neuritis; it is relieved, however, by holding the arm above the head, for example, during sleep.

In the paralytic group, the pressure symptoms are referred to the first dorsal, or first dorsal and eighth cervical roots. The paralysis is most marked in the muscles of the thumb, and becomes less towards the ulnar side; the affected muscles atrophy, especially those forming the thenar eminence, and the finer movements of the thumb and fingers are impaired.

When pressure symptoms are present, the extra rib should be removed through an incision which exposes the posterior triangle sufficiently to admit of the bone and its periosteum being excised, without damage being inflicted on the brachial plexus, the subclavian artery, or the pleura.

Similar clinical features to those of cervical rib may be caused by a prominent transverse process of the first thoracic vertebra and similarly got rid of by its removal.

_Branchial cysts and branchial tumours_ are described with tumours of the neck (p. 598).

WRY-NECK OR TORTICOLLIS.--The term wry-neck or torticollis is applied to a condition in which the head assumes an abnormal attitude, which is usually one of combined lateral flexion and rotation.

The most important form is due to faulty action of the cervical muscles, and three varieties of muscular wry-neck are recognised--(1) the acute or transient; (2) the chronic or permanent; and (3) the spasmodic.

#Acute# or #transient wry-neck#--so-called "rheumatic torticollis"--comes on suddenly, usually after the patient has been exposed to a draught of cold air or to damp. The condition is popularly known as "stiff neck," and is probably associated with fibrositis of the affected muscles. The sterno-mastoid, and often the trapezius, are contracted, and pull the head to one side, twisting the face slightly towards the opposite side (Fig. 270). There is tenderness on pressing over the affected muscles, and sometimes over the vertebral spines, and in the lines of the cervical nerves, and severe pain on attempting to move the head. Usually in the course of a few days the condition passes off as suddenly as it came on, but in some cases a certain amount of wasting of the affected muscles ensues.

In the _diagnosis_ of this form of wry-neck it is necessary to exclude such conditions as cellulitis, inflammation of the cervical glands, and disease of the cervical spine, in which the head may assume an abnormal attitude, the position being that which gives the patient greatest comfort.

The _treatment_ consists in ensuring free action of the bowels and kidneys, in inducing hyperaemia by means of heat, and applying gentle massage. Salicylates and similar drugs are useful in relieving the pain.

#Permanent# or #true wry-neck# is due to an organic shortening of the sterno-mastoid muscle. The trapezius, the splenius, the scaleni, and the levator scapulae muscle may also undergo shortening, along with their investing sheaths derived from the cervical fascia.

The sternal head of the sterno-mastoid is always markedly shortened, and stands out as a tight cord; sometimes the clavicular head is also prominent.

There is evidence that in the majority of cases the deformity results from some interference with the development of the muscles during intra-uterine life. This is probably the effect of undue pressure on the foetus diminishing the arterial supply to the central part of the muscle, with the result that the muscle fibres undergo degeneration with subsequent sclerosis and contraction. It may result also from cicatricial contraction of the muscle following rupture of its fibres during delivery. In such cases there is a history that the birth was a difficult one, the presentation having been abnormal; and that a swelling was observed in the sterno-mastoid shortly after birth. This swelling--_a haematoma of the sterno-mastoid_--is at first soft, later becomes smaller, and eventually disappears. In course of time, sometimes months, sometimes years after the disappearance of the swelling, shortening of the muscle takes place, and the deformity is established.

_Clinical Features._--Although the condition is usually described as "congenital," it is the common experience in practice that the child has reached the age of from seven to ten years before advice is sought. The appearance of the patient is characteristic (Fig. 271). The shortening of the sterno-mastoid pulls the head towards the affected side, usually the right, so that the ear is approximated to the shoulder. At the same time the head is rotated towards the opposite side and slightly tilted backwards, with the result that the chin is directed towards the opposite side, and is somewhat raised. The shortened sterno-mastoid stands out prominently, and, on any attempt to straighten the head, can be felt as a firm, fibrous band. The skin of the affected side of the neck may be thrown into transverse folds. The patient is unable to correct the deformity, but it is usually possible to diminish it by manipulation.

If the condition is not corrected, all the structures on the affected side of the neck undergo organic shortening, with the result that the deformity becomes accentuated. In advanced cases a lateral curvature, with the convexity towards the normal side, occurs in the cervical region, the vertebrae becoming wedge-shaped from side to side, and a compensatory curve may develop in the thoracic region (Fig. 272).

There is also asymmetry of the head and face, the affected side being the smaller. The eye on this side lies on a lower level, and is more oblique than its neighbour, the cheek is flattened, and the mouth asymmetrical. Instead of the eyebrows and the lips forming parallel lines, their axes converge towards the side of the contracted muscles and fasciae.

_Treatment._--While it may be possible when the condition is recognised during infancy to counteract the tendency to contraction and deformity by manipulations, massage, and exercises alone, it is usually necessary to divide the shortened structures as a preliminary to orthopaedic measures.

Subcutaneous tenotomy--at one time the favourite method of treatment--has been entirely replaced by the _open operation_, which admits of all the structures at fault, including the cervical fascia, being thoroughly divided, without risk of injuring other structures in the neck. The result of division of the shortened tissues is seen at once in a marked increase in the interval between the sterno-clavicular joint and the mastoid process. As in other deformities, the operation is only a preliminary, although an essential one, to the treatment by massage, movement, and exercises which must be persevered with for months, and it may be for years. When the torticollis attitude has been corrected in childhood, the asymmetry of the skull disappears.

#Spasmodic wry-neck# is the term applied to a condition in which clonic contractions of certain muscles produce jerkings of the head. The muscles most frequently at fault are the sterno-mastoid and trapezius of one side, and the posterior rotators of the opposite side. By these muscles the head is pulled into the wry-neck position, and is at the same time retracted, and there is more or less constant nodding or jerking of the head.

The condition is usually met with in adults of a neurotic disposition who are in a depressed state of health, and is due to some lesion, as yet undiscovered, in the nerve mechanism of the affected muscles--most probably in their cortical centres. It would appear that in some cases the spasmodic jerkings are originated by certain movements habitually made by the patient in the course of his work. In others, as a result of astigmatism and other errors of refraction, the patient has acquired the habit of repeatedly tilting his head to enable him to see clearly, and these movements have become continuous and uncontrollable.

The affection tends to become progressively worse until the patient is incapacitated for work or enjoyment. Sleep even may be interfered with.

_Treatment._--In well-marked cases the use of drugs, electricity, or restraining apparatus is never curative, but these measures combined with massage have been temporarily beneficial in milder cases.

Of the operative procedures, resection of portions of the accessory nerve on one side, and of the posterior primary divisions of the first five cervical nerves on the opposite side, seems to offer the best prospect of recovery. Simple division of these nerves or resection of the accessory alone has not proved permanently curative. Open division of the offending muscles without interfering with the nerves has given good results, and is a much simpler operation (Kocher).

Spasmodic wry-neck must be distinguished from the #hysterical# variety, which after lasting for weeks, or even months, may pass off completely, but, like other hysterical affections, is liable to recur.

Deviations of the neck simulating torticollis may occur in cervical caries, and in unilateral dislocation of the spine.

The #cicatricial contraction# of the integument of the neck that results from extensive burns, abscesses, or ulcers, may cause unsightly deformity and fixation of the head in an abnormal attitude, and call for surgical treatment. The contraction which follows the disappearance of a gumma of the sterno-mastoid may also produce a deformity resembling wry-neck.

INJURIES

#Contusion# of the neck may result from a blow or crush, as, for example, the passage of a wheel over the neck, or from throttling, strangling, or hanging. In medico-legal cases the distribution of the discoloration should be carefully noted. When due to throttling, the marks of the fingers may be recognisable, and nail-prints may be present. In cases of strangling, the mark of the cord passes straight round the neck, while in suicidal hanging it is more or less oblique and is higher behind than in front. When due to a direct blow, for example by a fist, the discoloration is limited, while it is usually diffused over the neck when due to the passage of a wheel over the part.

The clinical importance of these injuries depends on the complications that may ensue; for example, extravasation of blood under the cervical fascia may press upon the air-passage and oesophagus to such an extent as to cause interference with breathing and swallowing; the larynx or the trachea may be so grossly damaged that death results immediately from suffocation, or later from gradually increasing oedema causing obstruction of the glottis. If the mucous membrane of the air-passage or the apex of the lung and its investing pleura is torn, emphysema of the connective tissue may develop and spread widely over the body. In contusions of the lower part of the neck the cords of the brachial plexus may be injured.

#Fractures of the Hyoid, Larynx, and Trachea.#--The _hyoid bone_, on account of its mobility and the protection it receives from the body of the mandible, is seldom fractured, except in old people in whom the great cornu has become ossified to the body of the bone. It is usually broken either by a direct blow, or by transverse pressure as in garrotting. The fracture is almost always at the junction of the great cornu with the body, and there is marked displacement of the fragments, which may injure the pharyngeal mucous membrane.

The _thyreoid and cricoid cartilages_ are also liable to be fractured in run-over accidents, particularly in old people after calcification or ossification has taken place.

The _trachea_ may be lacerated, or even completely torn from the larynx, by the same forms of injury as produce fracture of the laryngeal cartilages.

The _clinical features_ common to all these injuries are swelling and discoloration; and if the mucous membrane is torn, air may escape into the tissues and produce emphysema. There is always more or less difficulty in breathing, which may amount to actual suffocation, and this may come on immediately, or in the course of a few hours from oedema of the glottis. Blood may pass into the lungs and be coughed up. Swallowing is usually difficult and painful, especially in fracture of the hyoid bone. There is also pain on speaking, the voice is husky and indistinct, and spasmodic coughing is common. When blood has entered the air-passages there is considerable risk of septic pneumonia.

_Treatment._--As the immediate risk to life is from suffocation, it is usually necessary to perform tracheotomy at once. In fracture of the hyoid the fragments may be replaced by manipulation through the mouth, after which the head and neck are immobilised by a poroplastic collar.

#Wounds--Cut-throat.#--The most important variety of wound of the neck met with in civil practice is that known as "cut-throat"--an injury usually inflicted with suicidal, less frequently with homicidal intent.

Suicidal wounds are usually directed from left to right (if the patient is right-handed), and they run more or less obliquely from below upwards across the neck; the wound being deepest towards its left end, that is where the weapon enters, and gradually tailing off towards the right. In most cases the would-be suicide throws his head so far back at the moment of inflicting the wound, that the main vessels are carried backward under cover of the tense sterno-mastoid muscles, and so escape injury. The knife may even reach the vertebral column without damaging the contents of the carotid sheath.

Homicidal wounds are usually more directly transverse, and are of equal depth throughout. The main vessels are generally divided, the oesophagus and trachea opened into, and in some cases the vertebral canal is opened and the cord and its membranes injured.

_Clinical Features._--The clinical features vary with the level of the wound and with its depth. In all cases the contraction of the platysma causes the wound to gape widely, and its edges tend to be turned in.

In a large proportion of suicidal attempts the patient only succeeds in inflicting one or more comparatively superficial wounds across the front of the neck. In many cases the haemorrhage from these is trifling, but if the external jugular and other large superficial veins are divided, it may be fairly profuse, although it is seldom immediately fatal, unless the blood is sucked in to the wounded air-passage.

Occasionally, but rarely, the wound is made _above the hyoid bone_, and opens directly into the mouth. There may then be sharp haemorrhage from the base of the tongue or from the lingual and external maxillary (facial) arteries or their branches in the submaxillary region, and asphyxia may result from the base of the tongue and the epiglottis falling back and obstructing the larynx.

The _hyo-thyreoid membrane_ is frequently divided, and the pharynx thus opened. As the depressor muscles of the hyoid are divided, there is interference with deglutition and phonation, but respiration is not affected. In such cases the upper portion of the epiglottis is often cut off, and the base of the tongue, the tonsil or the soft palate may be injured. The lingual, external maxillary and superior thyreoid arteries, and the hypoglossal nerve are also liable to be divided at this level, but the main vessels of the neck usually escape. There is pain and difficulty in swallowing, and food and saliva tend to escape through the wound. Particles of food may pass into the air-passages and cause violent fits of coughing.

In more severe cases the knife enters the _larynx_ or the _trachea_. Sometimes the thyreoid cartilage is divided--as a rule only partly--and the vocal cords are injured; in other cases the trachea is opened, or it may be completely cut across. The bleeding is serious, as the superior thyreoid arteries are usually damaged. If the common carotid and the internal jugular vein also are wounded, the haemorrhage usually proves fatal. The fatal issue may be contributed to by blood entering the air-passages and causing asphyxia, or by air being sucked into the open veins and causing air embolism. The laryngeal branches of the vagus may be divided and paralysis of the larynx ensue.

In all cases there is more or less dyspnoea and persistent coughing. The voice is husky, and the patient can only express himself in a hoarse whisper. There is difficulty in swallowing, and the food may enter the trachea. When the external wound is small, there may be a considerable degree of emphysema of the cellular tissue.

The _prognosis_ depends largely on the general condition of the patient. The majority of those who attempt to take their own lives are in a low state of health from alcoholic excess, mental worry, privation or other causes, and many succumb even when the wound in the neck is comparatively slight. Shock, loss of blood, asphyxia from blood entering the air-passages, and oedema of the glottis are the most frequent causes of death soon after the injury. Cellulitis, inhalation, pneumonia, and delirium tremens are later complications that may prove fatal.

_Treatment._--The first indication is to arrest haemorrhage, and this may be done by applying digital compression over the bleeding points. The bleeding vessels are then sought for and ligated, the wound being enlarged if necessary.

If the food and air-passages are intact, any muscles that have been divided should be sutured.

When the epiglottis is cut across in wounds opening into the pharynx, it should be united, preferably with fine silk sutures, as catgut is absorbed before healing has time to take place. The wall of the pharynx and the muscles should then be sutured layer by layer.

When the air-passage is opened, it is usually advisable to introduce a tracheotomy tube (Fig. 273), and pack gauze round it to avoid the risk of oedema of the glottis and to prevent blood entering the lungs. The soft tissues may then be brought together layer by layer.

In all cases the superficial part of the wound should be drained, and in applying the bandage the head should be flexed on the chest to take all tension off the stitches. The patient must be kept under constant supervision lest he should interfere with the dressings, or make a further attempt on his life. In some cases it is necessary to feed him through a tube passed into the stomach either through the mouth or through the nose; when this is not feasible, nourishment must be given by the rectum, or by a gastrostomy tube (Fig. 273).

_Wounds of the thoracic duct_ have been described with affections of the lymphatics (Volume I., p. 324), and _wounds of the brachial plexus_ with injuries of individual nerves (Volume I., p. 360).

INFECTIVE CONDITIONS

#Cellulitis# may occur in any of the cellular planes in the neck, the most important form being that which occurs under the cervical fascia, for example in the course of acute infective diseases, such as scarlet fever, measles, or pyaemia. The pus tends to spread widely throughout the neck, infiltrating the connective-tissue spaces around the blood vessels, the air-passages, and the oesophagus. The density and tension of the cervical fascia cause the pus to burrow downwards towards the mediastinal spaces of the thorax, where it may give rise to such complications as empyema, infective pericarditis, or gangrene of the lung. The pus may also reach the axilla by spread of the infection along the subclavian vessels.

An acute phlegmonous peri-adenitis sometimes occurs in the loose cellular tissue around the submaxillary gland, and spreads with great rapidity through the cellular planes of the neck. The condition--which goes by the name of _angina Ludovici_--is usually met with in adults, and appears to originate in some infective focus in the mouth.

_Clinical Features._--In all forms the process spreads rapidly, and the neck becomes swollen, brawny, and of a dusky red colour. The head is flexed towards the affected side, and there is pain on movement and on palpating the swelling. Pus forms early, but, as it is under great tension, fluctuation can seldom be detected. Respiration may be interfered with by pressure on the air-passages, or by the onset of oedema of the glottis, and tracheotomy may be urgently called for. Swallowing may also be affected by pressure on the pharynx and oesophagus. Pressure on the important nerves traversing the neck may give rise to irritative or paralytic symptoms. The main vessels may become thrombosed or eroded--particularly when the cellulitis is associated with scarlet fever--and in the latter case copious haemorrhage may follow incision of the abscess.

There is always marked constitutional disturbance, as evidenced by rigors, high temperature, a small, rapid pulse, and delirium; and death may result within a few days from toxaemia.

_Treatment._--In the earliest stages hot fomentations or ichthyol and glycerine should be applied, but if the process does not begin to abate within twenty-four hours, and if the swelling becomes brawny in character, one or more incisions should be made through the deep fascia where the signs of inflammation are most intense, and the deeper planes of the neck opened up by dissection. Drainage is secured by tubes or strips of rubber tissue. If profuse haemorrhage occurs it may be necessary to ligate the main artery lower in the neck.

#Actinomycosis# manifests itself in the neck as a diffuse, painless swelling, which slowly infiltrates the superficial structures, becoming brawny at some places, and at others breaking down and forming sinuses from which the ray fungus escapes in the discharge.

#Boils and carbuncles# frequently occur on the back of the neck, where the skin is thick and coarse and is rubbed by the collar.

The affections of the _cervical lymph glands_ have already been described (Volume I., p. 330).

TUMOURS

#Cystic Tumours.#--A great variety of cystic tumours is met with in the neck.

#Branchial cysts# are formed by the distension of an isolated and unobliterated portion of one of the branchial clefts. They usually form in connection with the third cleft, and are met with in the region of the great cornu of the hyoid bone, to which the wall of the cyst is almost always attached. Less frequently they take origin in the second cleft, and lie below the mastoid process, in which case the cyst is adherent either to the mastoid or to the styloid process. In some cases these cysts project towards the floor of the mouth. When near the skin they are of the nature of _dermoid cysts_, being lined with squamous epithelium and filled with sebaceous material. When deeply placed, they are lined by cylindrical or ciliated epithelium and contain a glairy mucoid fluid.

Although of congenital origin, these cysts do not usually attract attention till about the age of puberty, when they are noticed as small, soft, fluctuating tumours over which the skin moves freely. They grow slowly, but may attain great dimensions. The only treatment that yields satisfactory results is complete excision.

The _cystic lymphangioma_, _hygroma_, or _hydrocele of the neck_ (Fig. 274), has been described with affections of lymphatics (Volume I., p. 327); and _thyreo-glossal cysts in the neck_ at p. 583.

_Blood Cysts._--These may originate in a diverticulum of a vein that has become isolated, or in a cavernous angioma; or they may be due to haemorrhage taking place into a branchial or thyreo-glossal cyst. The diagnosis is often only possible by exploratory puncture; and the treatment consists in complete excision.

_Cystic Bursae._--Cystic degeneration may occur in the supra-hyoid and thyreo-hyoid bursae, and give rise to a rounded swelling which moves with the thyreoid on swallowing, and is only troublesome from the disfigurement it causes. It is treated by excision.

#Solid Tumours#, apart from the common enlargements of lymph glands, and the various forms of goitre, are not often met with in the neck.

The _circumscribed lipoma_ usually occurs over the nape of the neck or in the supra-clavicular region. It may attain considerable size, and from its weight become pedunculated and hang down over the back or shoulder.

_Diffuse lipomatosis_ usually begins over the nape and spreads more or less symmetrically till it completely surrounds the neck. As the new-formed fat is not encapsulated, extirpation of the mass is difficult and is seldom called for.

_Fibroma_ originating in the ligamentum nuchae, or the periosteum of the vertebral processes, is of slow growth, but it may attain considerable size, and on account of its deep attachments the operation for its removal may be difficult.

_Mixed tumours_ like that described as occurring in the vicinity of the parotid, and taking origin from branchial rests, are sometimes met with in the upper part of the anterior triangle.

_Osseous_ and _cartilaginous tumours_ occasionally grow in connection with the transverse processes of the lower cervical vertebrae.

_Sarcoma_ and _fibro-sarcoma_ of the slowly growing type may develop from any of the fascial structures in the neck, or from the connective tissue surrounding the blood vessels. In those taking origin beneath the sterno-mastoid, there is difficulty in removing them completely on account of their deep attachments, and when they are found to infiltrate the surrounding tissues the attempt should be abandoned. This rule may be relaxed in view of the aid that may be afforded by the insertion of a tube of radium, which is capable of rendering inert such portions of the growth as are not capable of being removed. Sacrifice of the common carotid artery is attended with the risk of hemiplegia and cerebral softening, especially in persons over fifty; resection of a portion of the vagus is less dangerous to life than stimulation by irritation of its fibres; resection of the internal jugular vein and of the cervical sympathetic cord are factors which add to the shock of the operation but do not carry with them any special risk.

_Carcinoma._--The commonest form of primary cancer is the _branchial carcinoma_, a squamous epithelioma which originates in connection with the second visceral cleft (Fig. 276). It appears as a rule under the sterno-mastoid at the level of the hyoid bone, and extends towards the submaxillary region, infiltrating the muscles and the sheath of the vessels.

It is more common in men than in women, and there is often a history of a small swelling having been present for many years, or even since birth. About middle life more active growth begins, the swelling becomes more fixed and is painful, and once it begins to grow, it increases rapidly and within a month or two may reach the size of a child's head. In spite of its size, however, it seldom causes interference with breathing or swallowing, and it has comparatively little effect on the general health. Clinically, the induration and fixation of the tumour suggest its epitheliomatous character, but the absence of a primary growth in the mouth or pharynx excludes its being a metastasis in the lymph glands.

Unless completely removed at an early stage, recurrence inevitably takes place.

Primary carcinoma may also occur in a supernumerary thyreoid, and in the para-thyreoid glands.

We have met with a case of _paraffin epithelioma_ on the neck, and a similar type of epithelioma may be met with in a lupus or a burn of long standing.

#The Thymus Gland.#--The thymus gland begins to diminish in size towards the end of the second year, and by the time puberty is reached it has entirely disappeared. In some cases, however, the process of involution fails to take place, and the gland may even undergo hyperplasia and exert pressure on the trachea, the great blood vessels, or the left vagus nerve and its recurrent branch. The enlargement of the thymus may be part of a general lymphatic hyperplasia--known as the _status lymphaticus_.

The pressure effects may be entirely referable to the trachea--_thymus stenosis of the trachea_--giving rise to progressive dyspnoea accompanied by stridor, with paroxysmal exacerbations during which the child becomes asphyxiated. It is only expiration that is interfered with, as with each inspiratory effort the gland is sucked in towards the mediastinum and so frees the air-passages, while with expiration it rises again, and, becoming jammed in the upper opening of the thorax, exerts pressure on the trachea, and during expiration a soft swelling is sometimes recognisable in the episternal notch. The paroxysms occur at irregular intervals, and any one of them may prove fatal. In some cases the symptoms seem to be associated with pressure on the blood vessels and nerves rather than on the air-passages, and in these there is distension of the veins and a tendency to syncopal attacks.

The only way to afford relief is to expose the gland and withdraw it from behind the sternum by making traction on its capsule. If the breathing is not thereby improved, the capsule should be opened and the gland shelled out.

The term _thymic asthma_ has been applied to another form of disturbed respiration due to a large thymus, which comes on suddenly in infants otherwise apparently healthy. Without warning, the child seems to choke, has great difficulty in breathing, with inspiratory stridor and indrawing of the epigastrium; he rapidly becomes cyanosed, and in the majority of cases dies in a few minutes--_thymus death_. No satisfactory explanation of the sudden onset of the symptoms is forthcoming, but it appears to be associated with something which suddenly narrows the mediastinal space, such as backward bending of the head, or venous engorgement of the thymus gland. Cases are recorded in which an attack has come on during the administration of a general anaesthetic; in some instances the patient has suffered from the generalised status lymphaticus.

#Tumours of the Carotid Gland or Glomus Carotica# (_Potato-like tumour of the neck_).--The carotid gland under normal conditions is about the size of a grain of corn, and lies to the posterior aspect of the bifurcation of the carotid. It is sometimes the seat of _endothelioma_. The tumour has a definite capsule, is moderately firm and elastic, increases in size slowly and gradually for a time, and then may grow more rapidly. Its relation to the vessels is characteristic: as it grows it envelops the common carotid and its branches, and becomes adherent to the internal jugular vein; and it may come to implicate the nerves in the neck, particularly the vagus and its recurrent branch, and the cervical sympathetic.

It gives rise to few symptoms, and in the majority of cases the surgeon is consulted on account of the disfigurement resulting from the presence of the swelling in the neck. This swelling is ovoid, smooth or slightly lobulated; it lies at the level of the bifurcation of the carotid, and tends to grow upwards rather than downwards; it is movable from side to side, but not up and down; it lies under the sterno-mastoid, and the skin is not implicated. There is transmitted pulsation in the tumour, but no expansion.

The diagnosis has to be made from lymphoma, adenoma, tuberculous glands, sarcoma, and carcinoma.

In a large proportion of the cases operated upon it has been necessary to ligate the carotids and to excise portions of the internal jugular vein, and as severe cerebral symptoms are liable to ensue the mortality has hitherto been high. Operation is therefore only to be recommended when the growth is rapid, or the symptoms have become urgent.