Malformations of the larynx are neither numerous nor specially important. The parts may be unsymmetric or there may be a fistula resulting from the imperfect closing of a branchial cleft.

Acute laryngitis or inflammation of the larynx results from exposure to cold, from inhalation of irritating vapors and substances, or is due to infections secondary to disease of the mouth, pharynx, or lung. It begins with a congestion and swelling of the mucosa. This is followed by increased secretion with disturbances of the voice due to involvement of the vocal cords. There is a round-cell infiltration of the tissue with sometimes ulceration, in the healing of which scar tissue forms.

Chronic laryngitis often follows acute attacks or it may develop independently. In it there is dilatation of the vessels and hypertrophy of all the portions of the mucosa. There is a slight thick secretion and the membrane looks distinctly granular on account of the swollen glands, granular laryngitis. Is generally found in singers and lecturers.

Edema may occur slowly, as in passive congestion and in chronic inflammations, or it may take place very rapidly (acute edema of the glottis) as a result of some sudden and severe inflammatory process, as from the inhalation of steam, gases, or the action of irritating substances. In it there is a serous infiltration of the arytenoid cartilages and the aryteno-epiglottic folds. These swollen tissues meet in the middle and more or less completely obstruct the passage of air into the lungs, sometimes causing death.

In diphtheria of the larynx, which may be primary or secondary to that of the pharynx, there is an acute inflammatory process with marked exudation. This contains much fibrin and, undergoing coagulation, forms a pseudo-membrane. In it, besides the fibrin, are found pus cells, desquamated epithelium, bacteria, and sometimes a few red cells. This membrane is grayish in color, tough, and when removed leaves a raw bleeding surface.

It may occur as an extensive layer over the larynx or in isolated areas. It may be removed, but reproduces very rapidly.

Although a pseudo-membrane is more commonly caused by the diphtheria bacillus, it may result from streptococci or from the action of irritating vapors.

Tuberculosis of the larynx is quite common as a primary lesion, usually being an infection on top of a chronic inflammation. May be secondarily infected by tuberculous material from the lungs. It generally appears in the form of scattered miliary tubercles which frequently break down and ulcerate. This occurs rapidly on the vocal cords. The lesions are most common about the posterior commissure, the arytenoid cartilages, and the true vocal cords, seldom on the epiglottis.

The ulceration may be very destructive, involving the sub-mucosa and even the cartilages, causing inflammation and necrosis of them.

The larynx may be the seat of the slowly spreading form of tuberculosis known as lupus.

Syphilis may be either of a mild or a very severe type, the commonest form being a simple catarrhal laryngitis with infiltration of the mucosa and submucosa. Gumma may form in the submucosa, break down, and give rise to extensive ulceration, with perichondritis and necrosis. As the healing processes go on, large amounts of fibrous connective tissue are formed. These undergo contraction with frequently marked deformity, greatly interfering with speech.

Leprosy gives rise to nodular lesions, quite similar to what may be found in syphilis. They break down, ulcerate, and in healing form large scars.

Glanders is rarely found. In it there is a cellular infiltration with the formation of suppurating ulcers.

Foreign bodies of various sorts may gain entrance and become lodged in the larynx.

Tumors

The most common tumors are the papillomata. They vary greatly in size and shape and the greater number are of inflammatory origin. They consist of a more or less dense framework of fibrous tissue covered by a layer of epithelium. These growths may be quite flat and but little raised above the surrounding surface, or they may be distinctly polypoid. The fibrous tissue may show mucous changes, and the glandular structures be distended with secretion, so as to form cyst-like growths.

Small fibromas are sometimes found. Adenomata are rare.

Malignant tumors may occur; of these, the sarcoma is very rare. When present, it does not involve the cervical lymph-nodes. The epithelioma is more common and may arise from either the vocal cords and ventricles or from the arytenoid folds and the epithelium covering the cartilages.