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.
Fig. 275.—Lympho-sarcoma of Neck.
(Mr. D. M. Greig's case.)
Fibroma originating in the ligamentum nuchæ, 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 vertebræ.
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.