How do doctors check for breast cancer after a mastectomy?

See below: Hi, despite all the breast tissue being removed, there is always microscopic breast cells that may be under the skin. The doctors will check all the skin at the mastectomy site to "feel" if there is local recurrence. They will also check the armpit as well to make sure there are no lymph nodes that are swollen.

General check ups: An oncologist is a cancer specialist who will examine the pateints and look for any local signs of recurrence in the breast(in case the breast was not removed with mastectomy) and also examine the chest area and the opposite breast. There are also blood tests, chest x-ray and ct scans to look for internal spread of cancer in the abdomen.