Yes. After a biopsy, the affected skin cancer may no longer be visible. Yet, the removed surface lesion can mean there is more under the surface. Additional tumor cells may remain in the skin. Sometimes the cells will grow downward and outward, like the roots of a tree. These cells may not be visible to the naked eye, but if they are not removed, the tumor will likely reappear. This will then require more extensive surgery. Neglected tumors can spread deep into the skin and intrude on nearby structures. In rare events, the cancerous cells can metastasize to lymph nodes and other organs in the body.