<prompt> Peptic ulceration occurs at all the following sites except -Lesser curvatureFirst part of duodenumLower end of esophagusStoma of gastric portion of gastrojejunostomy  <response>: Peptic ulcerUlcers are defined histologically as a breach in the mucosa of the alimentary tract that extends through the muscular mucosa into the submucosa or deep.Peptic ulcers are chronic, most often solitary lesions that occur in any portion of the gastrointestinal tract exposed to the aggressive action of acidpeptic juice.Peptic ulcers located in the following sites, in order of decreasing frequency :Duodenum, 1st portionStomach, usually antrumAt the gastro - esophageal junction in the setting of gastroesophageal reflux or Barretts esophagus.Within the margins of a gastrojejunostomy.In the duodenum, stomach or jejunum of patients with Zollinger -Ellison Syndrome.Within or adjacent to Meckels diverticulum that contains ectopic gastric mucosa. 