Genesis of papillary tumours: histological and microangiographic study

The technique developed to study the microangiography of healthy bladders has been applied to study the known vagaries of papillary tumours their associated changes and their genesis. Epithelial hyperplasia (reactive hyperplasia), which develops as a from mucosal self-defence, is a general, non-specific tissue response to an adverse environment. The conversion of reactive hyperplasia into reactive autonomy represents the neoplastic process. The growth of abnormal arteries precedes the development of tumours. A papillary tumour results from a symbiotic growth relationship between such an abnormal artery and the overlying normal or hyperplastic epithelium. All known vagaries of papillary tumours have been studied.