I have some white lesions on my tongue since last september. they sometimes disappear and pop up again. i am thought that maybe they are fungi.

Possible but...: Yes, that's possible but it could be many other things as well. You also may have more than one type of lesion. All lesions that last more than two weeks should be personally evaluated by an oral surgeon. If you smoke or drink alcohol you are at more risk of oral cancer. Please get it evaluated by seeing a dentist in person and don't take any chances with your life.

Can be deadly: White lesions in the mouth should be checked . There are many carcinomas of the mouth that start out as white lesions. However, there are also many white lesions that are benign. If the lesions are on the top part of your tongue and they come and go, you may have a candida (yeast infection). If those white lesions are from inflammation they could be leukoplakia which is precancerous.