The skin over the goitre is freely movable, and the tumour itself can be moved transversely, carrying the larynx and trachea with it, but it cannot be moved vertically. It moves up and down with the larynx on swallowing—a point of great diagnostic value. Of the mechanical symptoms dyspnœa is the most constant. It may only amount to shortness of breath on exertion, or the patient may suffer from sudden and severe dyspnœic attacks, especially when lying on the back during sleep, and such an attack may prove fatal. This may be due to the weight of the tumour pressing on the trachea, which has been softened and distorted by the goitre, or to temporary congestion and engorgement of the mucous membrane of the air-passages. In these cases there is marked stridor both on inspiration and expiration, but no aphonia. In rare cases the goitre presses upon the recurrent nerve, causing spasmodic dyspnœa, hoarseness, and aphonia from impaired movement of the vocal cords, and these symptoms, especially if accompanied by pain, raise the suspicion of malignancy. Disturbance of the heart's action may cause palpitation and sudden attacks of syncope; and pressure on the blood vessels may give rise to a feeling of fullness in the head, and giddiness.
The occurrence of hæmorrhage into the substance of the goitre or into a cyst, produces a sudden aggravation of the symptoms.
In intra-thoracic or retro-sternal goitre the tumour displaces and compresses the trachea and causes dyspnœa, and there are occasional paroxysmal attacks of breathlessness, which may be mistaken for asthma, particularly as the patient is usually the subject also of bronchitis and emphysema. In some cases the patient can, by a violent expiratory effort, such as coughing, project the goitre upwards into the neck. When the goitre is fixed in the thorax, the clinical features are those of a mediastinal tumour with lateral displacement of the trachea, and engorgement of the veins of the neck.
Treatment.—The patient should change his residence to a non-goitrous district. The evidence regarding the benefit derived from the internal administration of thyreoid extract, or of preparations of phosphorus or of iodine, is conflicting.
Operative treatment is indicated when there are symptoms referable to pressure on the air-passage, and in goitres which are steadily increasing in size. Kocher considers it advisable to operate if the patient becomes breathless on making pressure on the goitre from side to side. The suspicion of a goitre becoming malignant is also a reason for removing it by operation.
The operation—thyreoidectomy—consists in excising that portion of the thyreoid which is causing pressure symptoms, and this usually involves removal of one-half of the gland. The chief danger in operations for goitre is cardiac insufficiency, as evidenced by disturbed rhythm of the heart-beats, lowering of the blood pressure, or dilatation of the cavities of the heart (Kocher).
It is sometimes advisable to perform the operation under local anæsthesia. A general anæsthetic is, however, preferred in this country. The injection of 1/6th grain of morphin and 1/120th grain of atropin half an hour before the operation, and the administration of ether by the open method, or by intra-tracheal insufflation, is safe and satisfactory.
There is reason to believe that the absorption of thyreoid secretion squeezed from the divided surfaces gives rise to a condition known as acute thyreodism during the first few hours after operation; its symptoms are elevation of temperature, increase in the pulse-rate (150–200), rapid respiration with dyspnœa, flushing of the face, muscular twitchings, and mental excitement. The gentle handling of the tumour and the employment of a drainage tube for the first forty-eight hours diminishes this risk.
Tetany, as evidenced by the occurrence of cramp-like contractions of the thumb and fingers, may supervene within a few days of the operation if one or more of the para-thyreoids have been inadvertently removed. It may be controlled by large doses of calcium lactate. On no account may the whole of the thyreoid gland be removed, as this is followed by the development of symptoms closely resembling those of myxœdema—operative myxœdema or cachexia strumipriva.
Treatment of Sudden Dyspnœa.—When dyspnœa suddenly supervenes and threatens life, it is sometimes possible to relieve the pressure on the trachea by open division of the skin, superficial fascia, platysma and deep fascia in the middle line of the neck, so as to relax the tension on the goitre. If this is insufficient, the isthmus may be divided. Should relief not follow, tracheotomy must be performed, and a long tube or a large-sized gum-elastic catheter with a terminal aperture be passed along the trachea beyond the seat of obstruction.