What is worse a malignant tumor or benign tumor?

Usually malignant: Malignant tumors tend to spread all over the body. Benign tumors tend to spread locally. If a benign tumor is in a bad place, then local spread can be very serious. You can't always ignore a tumor just because it is benign.

Basics: Malignant means bad & most malignant tumors act badly and often lead to death. Benign means good and most benign tumors sit in place and do no harm. However, you can have a benign tumor arise in a bad place, say on an eyelid where it closes the eye and can lead to los of vision over time. Context matters.