The great latitude accorded the term "precancerous" has led to its application to a variety of lesions both cancerous and noncancerous. For the sake of clearness in thinking it would be well to keep separate those lesions which may ultimately terminate in cancer from those cases which have recently assumed definite malignancy. It is of the greatest importance to the patient, however, that a malignant condition be eradicated completely while it is still a local process.
The majority of so-called precancerous lesions represent an incomplete or perverted reaction to some form of chronic irritation. When the cells of any tissue are injured or destroyed, there is an attempt at repair, and the neighboring cells are stimulated to reproduction. Normally the development of these cells goes on at a rate equal to or greater than that of the most malignant of tumors, and they soon reach maturity. In son1': cases, however,