A case of vanishing bone disease is presented, with radiologic, endoscopic, and peritoneoscopic evidence of angiomatous involvement of the bones, surrounding soft tissues, and gastrointestinal tract. The diagnosis was made by a combination of radiologic techniques and endoscopy. Areas of absent bone were shown to opacify after intralymphatic injections of contrast material, providing in vivo demonstrations that these areas of vanishing bone are occupied by abnormal lymphatics. The etiology remains obscure, but our review of the literature suggests that this condition may be one of a large spectrum of disorders due to a basic underlying endothelial dysplasia. The lymphatic system, vascular system, or both may be involved, and the condition may manifest itself as an abnormality of the bones, soft tissues, viscera, or a combination of these.