Basal crypt dysplasia in Barrett's oesophagus: ready for prime time?

Barrett's oesophagus (BE) continues to rise in prevalence alongside oesophageal adenocarcinoma; understanding and identifying early neoplastic changes is critical. Crypt dysplasia (CD) in BE is an emerging concept characterised by dysplasia confined to the crypt base without surface involvement. Recent studies suggest that CD shares molecular alterations with low-grade and high-grade dysplasia, such as TP53 mutations and chromosomal instability, and may represent an early phase of neoplasia. Grading of CD remains inconsistent, with limited correlation to clinical outcomes, although classifying CD into low-grade and high-grade categories provides a practical diagnostic framework. High-grade crypt atypia typically warrants a diagnosis of CD, whereas low-grade crypt atypia poses greater diagnostic challenges and requires careful differentiation from reactive changes. This framework also incorporates exclusionary criteria, such as inflammation, ulceration and erosion. This review encompasses key features of CD, the diagnostic pitfalls encountered in clinical practice and the underlying biology driving crypt dysplasia. Future studies focusing on the natural history of CD, its molecular underpinnings and interobserver reproducibility will be pivotal in refining diagnostic criteria and improving patient outcomes in BE.