Final answer:
Benign masses typically have well-defined borders, although there are exceptions.
Step-by-step explanation:
The borders of a benign mass can vary depending on the type and location of the mass. In general, a benign mass will have well-defined borders that are smooth and regular. These borders may be easily distinguishable from the surrounding tissue. Examples of benign masses with well-defined borders include lipomas and fibroids. However, it is important to note that not all benign masses will have well-defined borders. Some benign masses, such as certain types of cysts, may have irregular or indistinct borders.