Which histological feature is indicative of Barrett's oesophagus?

Barrett's oesophagus is characterized histologically by the presence of goblet cells, which indicate intestinal metaplasia in the lower oesophagus. This condition arises as a result of chronic gastroesophageal reflux disease (GERD), where the normal stratified squamous epithelium of the oesophagus is replaced by a columnar-type epithelium typically found in the intestines. The presence of goblet cells signifies this transformation, showing that the squamous epithelial cells have undergone a metaplastic change to better withstand the acidic environment caused by reflux.

Though columnar type epithelium is also present in Barrett's oesophagus, it does not specifically indicate the distinct metaplastic change that is characterized by the presence of goblet cells. Squamous cell carcinoma and basophilic staining are not associated with Barrett's oesophagus as they pertain to different conditions or indicators. Thus, goblet cell metaplasia serves as a definitive histological marker for Barrett's oesophagus, making it the correct choice.