A tumor growing under the tongue may be malignant. 1. Tumor is a kind of disease caused by excessive proliferation of cells in the body under the action of tumorigenic factors. They can be divided into malignant tumors, benign tumors, junctional tumors and precancerous lesions. No matter which type of tumor, it can occur in any part of the body, and the tongue is certainly no exception. If an individual finds a tumor under his tongue, the possibility of malignant tumor cannot be ruled out. 2. The damage caused by malignant tumors is extremely serious, which will lead to a certain degree of threat to the safety of the individual’s life. Therefore, for those who have a tumor under the tongue, the pathological nature of the tumor must be clarified through scientific examination, and once diagnosed as malignant lesions, the treatment should be intervened as soon as possible in accordance with the doctor’s instructions.