Since the publication of the third edition there have been several changes in the pathology and classification of these lesions. The current edition updates the status of heart tumours, with emphasis on newer findings, especially molecular advances. In most cases, the authors have followed the classification of the World Health Organization, whose updated volume on tumours of the lung, heart, and mediastinum is forthcoming. Because newer imaging modalities, especially cardiac magnetic resonance imaging and 3-D echocardiography are increasingly used in preoperative evaluation of heart tumours, the authors have introduced a chapter devoted exclusively to radiologic diagnosis. In addition, inflammatory myofibroblastic tumour, a less common tumour of heart valves, is covered quite differently from the previous volume, since several reports and series of this childhood tumour have emerged. This atlas has carried over a discussion of lesions that are neither neoplastic nor hamartomatous, such as thrombi and some infections that can mimic tumours, because some of these lesions, especially thrombi, are among the more commonly-excised heart masses, and may present diagnostic challenge. This work is a useful source for physicians who wish to find a reference to classify a tumour of the heart, or update their knowledge of these lesions.