[Clinical symptoms of precancerosis].

Clinically, praecancerosis of the oral mucosa may be classified into the following groups: Whitish, flat changes, reddish changes, papillary changes and ulcers. Combination of the various groups and flowing transition between them is often observed. It can be shown that praecancerosis can be neither clearly distinguished from benign tumors or changes, nor can it be differentiated from already existing malignomas. The same picture of a disease can occur in various clinical aspects. On the other hand, histologically very different changes may often hardly be distinguished clinically. A change in the oral mucosa must therefore be regarded as possibly malignous as long as not proven to the contrary. Also, it is important to check, at regular intervals, changes diagnosed benign, since the possibility of malignous change cannot be ignored.