The pictures to the right show an esophagus, cut open to show its inside, from three different patients removed by surgery because it had cancer in it. Black arrows point to the cancer, blue arrows point to the normal pearly-white squamous lining of the esophagus, and green arrows point to the pink "velvety areas" of Barrett's metaplasia.
With endoscopic examination, cancer can be seen in some cases as ulcerating tumor as in the left picture or just as a growth or mass as in the middle picture. In many cases, however, cancer can be difficult to see. The far right picture is of an opened esophagus, showing that it has completely lost its normal squamous lining, which was replaced by Barrett's metaplasia with its typical pink velvety appearance. Can you spot the cancer in this picture? Of course not.
Many cancers that arise from Barrett's are not easily visible. For this reason, the gastroenterologist will take multiple pieces of tissue for pathology examination, even though he or she may not see any particular lesion while looking through the endoscope. It is the current practice to take one piece of tissue from each quadrant of the esophagus (left, right, front and back), known as "our quadrant biopsy." This is repeated every 2 cm throughout the length of the Barrett's segment. New endoscopic instruments available at the Baylor College of Medicine's Barrett's Center are equipped with high resolution imaging as well as narrow band technology allow better visualization of Barrett's esophagus as well as earlier cancer.