Pre malignant is just that. Not yet cancer. If it is small, it can be surgically removed. There are all grades of premalignant lesions, of many different types. Many that are low grade, only 10% of them, even untreated, never progress to malignancy. The path report should use the word dysplasia and high or low grade if it is moving from low to high grade, but even then, only 25% of all dysplasias move on to full malignancy. That will tell you a lot. Only a few are high grade dysplasia, those are serious.

If you are seeing an ENT, he is trained as a surgeon and he is going to want to do surgery. Please ask him for a copy of the pathology report and the people here can help you understand what this is - high risk, low risk - etc. Also if you wish to discuss this further, it would be helpful to know what risk factors your father might have, such as tobacco use.

For now, try to be calm, feel great that this was caught early whatever it turns out to be, as that means low risk of long term problems.