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].
Fig. 274.—Hygroma of Neck.
(Photograph lent by Mr. J. W. Dowden.)
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 hæmorrhage 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 Bursæ.—Cystic degeneration may occur in the supra-hyoid and thyreo-hyoid bursæ, 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.