Benign tumors—These noncancerous tumors are usually slow

• growing, have distinct borders, and are rarely life-threatening. They tend to stay in their primary location and don't spread to other parts of the body. Examples include fibroids in the uterus and lipomas in the skin. 
• Malignant tumors 

  These cancerous tumors grow rapidly and can invade other parts of the body. The new tumors that have spread are called metastases, or “mets,” and can come back after treatment. 

   

A doctor can use a variety of tests to determine if a tumor is benign or malignant, including:

• Imaging tests: X-rays, CT scans, and MRIs can help identify unusual growths that might be cancer. 
• Blood tests: These can also help with diagnosis. 
• Biopsy: This is the only way to confirm the presence of cancer. A biopsy involves removing a tissue sample