Manual of Surgery Volume Second: Extremities—Head—Neck. Sixth Edition.

by Alexis Thomson; Alexander Miles

Acute suppurative inflammation of the sublingual gland may occur under the same conditions as in the parotid, and is associated with the formation of an exceedingly painful and tender swelling under the tongue. The tongue is gradually pushed against the roof of the mouth, so that swallowing is difficult and respiration may be seriously impeded. There is marked constitutional disturbance. An incision into the swelling is immediately followed by relief of the symptoms.

Tuberculous disease of the salivary glands is rare. It usually begins in the lymph glands within the capsule of the parotid or submaxillary, and spreads thence to the salivary gland tissue.

Tumours.—Cystic Tumours—Ranula.—The term ranula is applied to any cystic tumour formed in connection with the glands in the floor of the mouth. Formerly these tumours were believed to be retention cysts due to blocking of the salivary ducts. They are now known to be the result of a cystic degeneration of one or other of the secreting glands in the floor of the mouth. They contain a thick glairy fluid, which differs from saliva in containing a considerable quantity of mucin and albumin, while it is free from any amylolytic ferment or sulpho-cyanide of potassium. Numerous degenerated epithelial cells are found in the fluid.

The sublingual ranula is the most common variety. It appears as a painless, smooth, tense, globular swelling of a bluish colour. It usually lies on one side of the frenum, and over it the mucous membrane moves freely. As it increases in size it gradually pushes the tongue towards the roof of the mouth, and so causes interference with speech, mastication, and swallowing. It is to be differentiated from a retention cyst of the submaxillary gland by the fact that a probe can usually be passed down the submaxillary duct alongside of the swelling, and from sublingual dermoid ([p. 539]).

The treatment consists in making an incision through the mucous membrane over the swelling, dissecting away the whole of the cyst wall if possible, and, if any portion cannot be removed, swabbing it with a solution of chloride of zinc (40 grains to the ounce), after which the cavity is stuffed with bismuth gauze and allowed to close by granulation. It is sometimes found more satisfactory to dissect out the cyst through an incision below the jaw, and in the event of recurrence this should be undertaken.

Cystic tumours, similar to the sublingual ranula, form in the other glands in the floor of the mouth—for example, the incisive gland, which lies just behind the symphysis menti, as well as in the apical gland on the under aspect of the tip of the tongue. The latter is distinguished by the fact that it moves with the tongue. In rare cases children are born with a cystic swelling in the floor of the mouth—the so-called congenital ranula. It is usually due to an imperfect development of the duct of the submaxillary or sublingual gland.

Solid Tumours—Mixed Tumours of the Parotid.—The most important of the solid tumours met with in the salivary glands is the so-called “mixed tumour of the parotid.” This was formerly believed to be an endothelioma derived from a proliferation of the endothelial cells lining the lymph spaces and blood vessels of the gland. A more probable view is that it develops from rests derived from the first branchial arch an not from the parotid. The matrix of the tumour is made up of cartilaginous, myxomatous, sarcomatous, or angiomatous tissue, the proportion of these different elements varying in individual specimens, and it may include some portions that are adenomatous. A gelatinous substance forms in the intercellular spaces of the tumour, and may accumulate in sufficient quantity to give rise to cysts of various sizes. There is reason to believe that the tumours of the parotid previously described as adenoma, chondroma, angioma, myxoma, and many of the cases of sarcoma, were really mixed tumours in which one or other of these tissues predominated.

The tumour usually develops in the vicinity of the parotid, and presses on the salivary tissue, thinning it out and causing it to undergo atrophy.

Clinical Features.—The mixed tumour is usually first observed between the ages of twenty and thirty. It is of slow growth and painless, and forms a rounded, nodular swelling, the consistence of which varies with its structure. The skin over the swelling is normal in appearance and is not attached to the tumour ([Figs. 263], [264]). Only in rare cases does paralysis result from pressure on the facial nerve.