Histopathology and the 'third great lie'. When is an image not a scientifically authentic image?

This article considers the issues of image manipulation within the context of electronic/digital images. The possibility for such alterations has occurred with the increasing availability of simple and cheap computer software, permitting modification of digitized images as a whole, or in part. The concepts of acceptable, through to unacceptable, manipulations are discussed using macroscopic and histological illustration examples. The legal and editorial problems that this poses for medical and scientific publishing are also discussed, alongside examples of previous fraudulent image publications and the historical context of valid scientific images.