What is a common characteristic of malignant tumors in relation to their mobility?

Malignant tumors are typically characterized by their tendency to adhere to surrounding tissues, which is why they are often fixed to adjacent structures. This fixation occurs because malignant cells can invade local tissues, disrupting normal boundaries and creating a more complex relationship with adjacent organs and structures. As a result, surgical removal becomes more challenging, as these tumors may not be easily separated from the tissues they have invaded. In contrast, benign tumors are generally more encapsulated and are often mobile and movable due to their distinct separations from surrounding tissue. The invasiveness of malignant tumors is a key factor in their potential to metastasize, but this particular characteristic of being fixed highlights the aggressive nature of these tumors in terms of their growth and interaction with normal anatomy.