TUMOURS IN THE FACIAL SINUSES AND CANCER OF THE SUPERIOR MAXILLA. 29 



with epithelial fungations. This form has been termed rodent cancer 

 of the maxilla. Even when the affection is discovered early, for 

 example at the moment when the buccal mucous membrane becomes 

 ulcerated, or when the face begins to show deformity, the body of 

 the maxilla or the alveoli of the teeth have already undergone extensive 

 injury. 



You must guard against founding your prognosis of tumours in the 

 region of the sinuses on the volume of the swelling, or distortion of 

 the facial bones. Whilst epitheliomata of the maxilla, even though 

 hardly visible, are of the greatest gravity, innocent tumours developed 

 from the mucous membrane of the sinuses may press against the 

 external wall of the cavity containing them, thinning, lifting, and 

 perforating it, and finally breaking through the skin. Such benign 

 tumours can be operated on with success. The animal is chloro- 

 formed, the invaded cavities freely opened — most frequently the two 

 maxillary sinuses are those affected — and the new growth totally 

 removed, either in one or several portions. Haemorrhage is checked 

 by plugging, or the use of the cautery. But in the case of truly 

 malignant tumours such operations are unjustifiable, and the practi- 

 tioner who wishes to avoid compromising his reputation will not 

 attempt them. 



In speaking of these tumours it is well, in animals as in man, to 

 reserve the epithet of malignant for those which grow rapidly, invade 

 neighbouring tissues— bone and soft parts — and which extend to the 

 lymphatics ; to those, in a word, whose course simulates the progress 

 of an infectious disease. 



I may summarise the practical deductions to be drawn from the 

 cases described in a few words : — Tumours developed on the mucous 

 membrane of the sinus, which have only affected the bone by mechani- 

 cally lifting it, or by exercising on it permanent prolonged pressure, 

 are curable. If the value of the animal justifies intervention they 

 should be removed. 



When, however, the new growth invades tissues indiscriminately 

 and has partially destroyed the walls of the sinus, or affected the 

 alveoli of the teeth, without, however, seizing on the lymphatic glands, 

 it is almost always of the nature of an osteo-sarcoma, and interference 

 is not advisable. 



Finally, when the tumour shows metastatic characters, and affects 

 neighbouring lymphatic glands, it is usually a malignant epithelial 

 tumour, beyond operation, and always liable to return if ablation is 

 attempted. 



