Assessment of Barrett’s Esophagus biopsies is hampered by substantial interobserver variability among pathologists, and current guidelines therefore recommend expert review of dysplastic cases. The definition of an expert pathologist in not really known however and at the same time, pathology services face increasing workload pressures and a shrinking workforce. Recent advances in artificial intelligence and digital pathology raise the possibility that AI systems could reduce diagnostic variability, improve diagnostic accuracy, and ultimately enhance patient outcomes.

Oesophagogastric cancer comprises a biologically heterogeneous group of malignancies in which histiotype remains a clinically relevant variable along rapid expansion of molecular testing. The upcoming 6th edition of the WHO classification of digestive system tumours retains morphology as the diagnostic gold standard, while refining the taxonomy of oesophageal and gastric epithelial malignancies, better defining poorly cohesive and neuroendocrine neoplasms, and incorporating clinically relevant molecular concepts including biomarker testing. This talk will review the new WHO framework for oesophageal and gastric tumours with emphasis on those histological categories that carry practical implications for pathologists. Particular attention will be given to the relationship between the WHO, the Lauren and the Japanese Classifications of upper gastrointestinal tumours, the significance of poorly cohesive and signet-ring cell morphology, recognition of rare gastric subtypes, and the current classification of neuroendocrine neoplasms.