Amongst the lesions just bordering on tumours may be mentioned the so-called Post-nasal adenoid growths. This name is a somewhat unfortunate one, and it should be remembered that the glands concerned are lymphatic follicles and not proper epithelial glands. The subject will be more fully considered in connection with the tonsils and naso-pharynx, which are liable to similar lesions.

Another form of lesion which has affinities with chronic inflammation is the Mucous polypus of the nares. Like other mucous polypi they occur very commonly as a result of chronic catarrh, but they appear occasionally without any apparent cause. They are usually in the form of rounded projections having a comparatively narrow base or neck, the growth becoming more pedunculated as it enlarges. They often produce much obstruction of the passages, and are not infrequently multiple. In structure some of them present simply the constituents of the inflamed mucous membrane, connective tissue with rather wide serous spaces, and covered with cylindrical ciliated epithelium. (If the epithelium be examined in fluid immediately after removal, the ciliary motion will be seen.) The connective tissue is usually so infiltrated with serous fluid as to give an oedematous appearance to the polypus, and sometimes a more definite cystic formation occurs. In some cases there are contained in the tumour mucous glands, but it is doubtful if there is a true new-formation of gland tissue. Cysts sometimes develop from dilatation of mucous glands contained in the tumour.

Polypi are sometimes found of a different character from those mentioned above. There may be true Papillomata. or there may be Myxomata or Fibromata taking the form of polypi. These latter usually take origin in the periosteum. Cysts are rare, if one excludes those arising from polypi. They are usually situated on the floor of the nose anteriorly. Malignant tumours sometimes assume the polypoid form.

Of the malignant tumours Sarcomas, originating mostly in the periosteum or perichondrium, may produce serious obstruction and deformities of the nasal structures. The sarcomas often dislocate the nasal bones, and involve the neighbouring structures in their substance. In this way they sometimes penetrate into the antrum, or involve the hud palate and alveoli. Cancers rarely occur in the nares as primary tumours, but may involve them by extension from neighbouring parts.