The suggestion that this paper should be presented emphasizes the difficulties encountered even by the most careful observers. Not only is there a danger that treatment, by operation or otherwise, may be instituted under a mistaken diagnosis of malignant disease, but there is another and even greater danger, that malignant change may be overlooked until the disease has progressed beyond the chance of cure.
It is desirable, therefore, to review the possible mistakes of omission and commission and to consider the means of avoiding them.
COMMON SOURCES OF CONFUSION
The diseases which most commonly cause confusion are: (a) chronic diffuse simple laryngitis; (b) hypertrophic laryngitis, hyperkeratosis and pachyderma; (c) syphilitic infiltration and leukoplakia; (d) tuberculous laryngitis, and (e) simple neoplasm. Any one of these conditions may simulate carcinoma so closely as to lead to the adoption of such drastic treatment as laryngectomy. On the other hand, a mistaken diagnosis of