If a person goes to a surgeon and asks for healthy tissue to be removed that is usually cause for having that person evaluated for mental illness.
"Healthy" is these days in the medical field defined as whatever is not causing the quality of life to deteriorate. In many consultations, patient's will / choice is taken into consideration.
1. Aesthetic surgeries are what most readily spring to mind on this topic. There are "healthy" tissue, but removed or modified to give the look a person wants.
2. There are growths in the body typically around joints, that are otherwise "healthy", but stop the normal limb movements or cause the limb movements to be painful. Those are also removed, of course, by taking patient's choice in mind by educating them about the risk. The patient can always be advised to just refrain from some limb movements, considering it is a sin to "kill" the healthy growth tissue around their joints that are very much "alive".
3. My sister's nose has a bone blocking 85% of one of the nostrils. That piece of bone is "healthy", except over decades of life this has caused nose allergies and an increase in likelihood of ear infections. If she had any sleep apnea like our father does, the nostril issue would have worsened it a lot. The doctors have completely left it to her whether or not to remove that "healthy" bone tissue. There are some risks and a lot of inconvenience to get the surgery done, and on the other hand there are these allergies.