I just had an upper GI endoscopy for schatzki ring. A biopsy was taken for a possibly thickened esophageal mucosa. What is the purpose of the biopsy?

Rule out cancer. A Schatzki ring is a narrowing of the lower esophagus that is caused by a ring of mucosal tissue that normally lines the esophagus. Since it occurs at a place in the esophagus that is also affected by reflux and may resemble Barrett's esophagus, which is inflammatory, biopsy can help distinguish the variety of pathologies that can be found in this area.
To make sure. There is not a concerning problem. Remember, there are many times something that appears abnormal may not be anything concerning when looking under a microscope.

Related Questions

Do I have to undergo an upper GI endoscopy and biopsy to determine if I have barrett's esophagus?

Yes. The diagnosis of barrett's esophagus is made by both endoscopic appearance of the mucosa of the esophagus as well as pathological features found on biopsy of the abnormally appearing mucosa. Additionally, these findings must be confirmed by repeat upper GI endoscopy before a diagnosis can be made. Read more...
Yes. Barrett's is a histological diagnosis. Tissue can look abnormal at endoscopy but a biospsy will confirm and exclude dysplasia (precancerous changes). Read more...