The basic pathology of Barrett's esophagus is -

Ans. is 'b' i.e., Metaplasia of squamous cells to columnar cells Barrett's esophaguso Is metaplastic change of distal esophageal mucosa from normal squamous epithelium to columnar epithelium, in response to chronic gastro-esophageal reflux.o The junction between squamous esophageal mucosa and gastric mucosa moves proximally.o Three types of columnar epithelium have been described in Barrett's esophagus:i) Intestinal type - the most common typeii) The junctional type andiii) The gastric fundic typeo Barrett's esophagus is a premalignant condition for adenocarcinoma esophaguso "The definition of Barrett's esophagus (BE) has evolved considerably over the past decade. Traditionally, BE was identified by the presence of columnar mucosa extending at least 3 cm into the esophagus. It is now recognized that the specialized intestinal type epithelium found in the Barrett's mucosa is the only tissue predisposed to malignant degeneration. Consequently, the diagnosis of BE is presently made given any length of endoscopically indentifiable columnar mucosa that proves on biopsy to show intestinal metaplasia." - Schwartz 9/e p831 (8/e, p868)Also remembero The hallmark of intestinal metaplasia is the presence of intestinal goblet cells.