A short lesson from Mark 11:23 on dealing with growths, tumors, etc. I would recommend you look up Mark 11 and go over the verses where Jesus spoke to the fig tree and then used it as an object lesson for teaching you that you can speak to a material object (which a growth or tumor is) and see it affected (removed) by YOUR WORDS.
Look at Mark 11:23 in particular and read it from various versions to enlarge your understanding.
Remember: Jesus is YOUR AUTHORITY that YOU CAN SPEAK to 'mountains' and see them removed.