176 THE LARYNX, BRONCHI AND OESOPHAGUS SALIVARY GLAND TUMOURS Pleomorphic adenoma and less commonly oxyphil-cell adenoma (oncocytoma) may occur in any salivary tissue in the supraglottis. The most usual site is the false cord and wide local removal is sufficient to cure the condition. HAEMANGIOMA This vascular tumour is most commonly diagnosed in the first 2 years of life, and may present on the cord or in the subglottis. Since spontaneous resolution often occurs no treatment need be undertaken in early childhood unless there is respiratory obstruction. If the growth is confined to the cord it may be removed at direct laryngoscopy. AMYLOID It is not only as a concomitant feature of a debilitating illness that amyloid disease of the larynx occurs. Although uncommon it has to be borne in mind in the differential diagnosis of the solitary laryngeal mass. It is removed locally, but it may require more radical surgery if it recurs. LARYNGOCELE Lower animals have air sacs and in some humans remnants of these remain and are situated in the laryngeal ventricle. If one expands to form a laryngo- cele it either grows outwards through the thyrohyoid membrane and appears in the neck (external laryngocele) or it extends upwards and presents as a swelling in the vallecula (internal laryngocele). The presentation is often an intermittent neck swelling with or without hoarseness. On other occasions if the neck of the sac is blocked the sac becomes infected and it presents as a pyocele. Laryngocele is often said to occur most commonly in trumpet players and glass blowers but a review of the literature shows this to be false. The relationship is that if a person has a residual air sac that is liable to form a laryngocele this will occur when pressure is put upon it by blowing. The blowing per se does not cause the laryngocele, it only brings it to the patient's attention. It may be diagnosed by the characteristic radiographic appearance (Fig. 80) when the large translucent sac is seen and is made larger by the Valsalva manoeuvre. Treatment is to approach the sac from the neck, dissect it free, remove the upper half of the thyroid lamina, locate the neck of the sac, ligate it and remove &e laryngocele. The repair line is reinforced by the strap muscles of the neck. CYSTS An internal laryngocele may resemble a supraglottic cyst but it is diagnosed and differentiated by the typical radiographic appearances. A cyst occurs mainly in the supraglottis where there are a large number of mucous glands and the mouth of one of these may become blocked to cause a mucous reten- tion cyst. Treatment is to uncap the cyst at direct laryngoscopy hoping that marstipialization will be permanent.