456 MUCOUS MEMBRANES. 



which are situated in the head, we find, apart from those can- 

 cerous affections of the lips, ej^elids, and alae nasi, which 

 property belong to the skin, a true soft glandular cancer of the 

 MUCOUS LINING OF THE NASAL Foss^. In adults, tliis is de- 

 veloped on a soil previously made ready for it by a chronic 

 hypertrophy of all the structural elements of the mucous mem- 

 brane ; in children, it occurs without an}^ preparatory stage. It 

 forces its way by preference into the antrum of Highmore, dis- 

 tends the upper jaw, and manifests itself as one of the several 

 varieties of what is known as '* cancer of the upper jaw." The 

 patient succumbs so rapidly to the attendant cachexia, that 

 surgeons are now very sh}^ of all operative interference. The 

 tumour is wholly made up of imperfectly developed gland- 

 tubuli, produced by an excessive proliferation of the epithelium 

 of the mucous follicles. 



§ 395. In the oral cavity, the tongue is a favourite seat of 

 cancerous disease. It usually takes the form of a squamous 

 epithelioma, which however, in accordance with the greater 

 delicacy of the normal squamous epithelium of the tongue, is 

 distinguished from the harder squamous epitheliomata of the 

 skin by its softness, and a tendency to speedy disintegration. 

 The quantity of blood-vessels, lax areolar tissue, and above all, 

 of wide tymph-paths with which the tongue is furnished, ren- 

 ders its parenchyma peculiarly favourable to the extension of the 

 morbid growth by infiltration. Hence the local mischief assumes 

 a former place in the history of the disease. The primary 

 nodule is nearly always situated on one or other edge of the 

 tongue. It is said that the irritation of a ragged and decaying 

 tooth may have some share in causing the cancer. This primary 

 nodule is usually extirpated by a V-shajDed incision. The disease 

 soon recurs however, and the operation has to be repeated ; with 

 each repetition, the interval between the extirpation and the 

 return of the disease grows shorter, until at last the entire 

 tongue is destroyed. Metastatic deposits may occur both in the 

 nearest lymphatic glands, and in the lungs ; these secondary 

 deposits however, are always of very subordinate importance. 



What is known as soft cancer of the tonsils, is a soft 

 lymphadenoid sarcoma which is very prone to invade the pala- 

 tine arches and the isthmus faucium (Choanen). 



§ 396. At the entrance to the RESPiRATORy tract we meet 



