A system for detecting abnormal tissue in a patient including an introducer cannula having a proximal opening and a distal opening. The system further includes a surgical instrument configured for selective insertion through the cannula. The surgical instrument further includes a tissue cutting opening positioned relative to the distal end of the introducer cannula when fully inserted through the introducer cannula. The system also includes a sensor configured to detect at least one property of the tissue of the patient. The sensor is located at a fixed distance relative to the distal end of the introducer cannula when the surgical instrument is inserted into the introducer cannula.
