Thank you for your question, and I am sorry to hear about the stress that this is causing you. There are many different things that can present in the fashion that you describe, so it is important to speak with your doctor
. Some of the most common problems include things such as inclusion cysts, when a pimple or something similar is trapped underneath the skin and forms a ball or knot deep to the skin. These can grow in some people, and in others they simply persist and are noticed to the touch or cosmetically. Treatment will usually require excision of the tissue that has been trapped beneath the skin. Other common problems that can present as a mobile mass deep to the skin include fatty tissue collections known as lipomas. These can appear on any body part, are soft and mobile, and can grow over time. Usually excision is also required to remove these as well. There are many other things that this could be, and obviously there is the concern that it could represent something as serious as a cancer. Time allows your doctor to determine if the mass is growing or if there are other concerning symptoms that warrant more aggressive treatment. Please speak with your doctor about your concerns.