[Dysplasia in glandular digestive tissues: new concepts, new classifications]

The term of dysplasia is currently used to designate morphological alterations, identifiable at microscopic examination, revealing the existence of an unequivocally neoplastic process, at an early, non-invasive, stage of its natural history. The pathologist bears the full responsibility for the diagnosis of dysplasia, based on a broad spectrum of cytological and architectural abnormalities. It is important to grade the severity of the dysplastic lesions, in order to help guide clinical management and choose the therapeutic strategy. The Vienna classification, proposed in 2000 as a compromise between the Western and Japanese concepts, is now used for classification and grading of digestive epithelial dysplasia. The major advantages of the Vienna classification are the use of uniform terminology worldwide, achievement of good diagnostic reproducibility between pathologists and clear and consensual clinical consequences. Its use is strongly supported by the recent international recommendations.