No matter how thorough the doctor is in removing old silicone implants it is usually impossible to remove a 100 % of old silicone.This should NOT be cause for alarm.It is perfectly OK.
With ruptured implants, one aims to remove as much of the silicone as possible. Often, it is contained in the capsule surrounding the implant which makes its removal much easier. If there is free silicone outside of the capsule extending into the surround tissues, it can be very difficult to remove all of it. Within reason, attempts are usually made to remove as much of this as possible but there are risks including permanent breast deformities in these areas due to to concommitant removal of the breast tissue. Silicone has not been shown to increase your risk for breast cancer.