Experimentally induced malakoplakia.

Malakoplakia was induced experimentally by introducing large amounts of crude endotoxin-antigen comples of 075 Escherichia coli (E. coli 12797 CDC 0 group 75) into the kidneys and testes of rats. First leukocytes, then granulation tissue composed mainly of characteristic macrophages, the so-called Hansemann cells, appeared around the endotoxin-antigen mass. On the eighth day following the injection, deposition of calcium phosphate into the cytosegresomes of macrophages began and acused the formation of the Michaelis-Gutmann bodies necessary for the diagnosis of malakoplakia. The induction of the same process in humans by E coli endotoxin seems to be possible.