[Histologic and autoradiographic studies on the significance and terminology of von Brunn's nests in biopsies of the bladder mucosa].

Von Brunn's nests have been investigated systematically by means of histology and autoradiography in 201 biopsies of tumour-free and tumorous urinary bladders. They show the same proliferation behaviour like the superimposed urothelium under normal conditions and with inflammatory, metaplastic and dysplastic changes. Their sheltered location permits definite diagnoses even with detached superficial urothelium. In case of cystic transformation, a distinction between pseudoglandular, pseudopapillary and cribriform types is possible. They have to be distinguished from genuine glandular metaplasias in von Brunn's nests. Normal and metaplastic von Brunn's nests do not represent precancerous stages. They are supposed to be a protected proliferation reserve.