Morphogenesis of calcium laden cytoplasmic bodies in malakoplakia of the skin: An electron microscopic study

Abstract

The origin and development of the Michaelis-Guttmann body are presentedin a case of malakoplakia of the skin from which coagulase positive Staphylococcus aureus was cultured. Electron microscopic observations indicate an orderly sequence of events that results in the formation of Michaelis-Guttmann bodies within single membrane limited cytosomes in the cytoplasm of histiocytes. The well developed Michaelis-Guttmann bodies are composed of closely packed, generally radially oriented, needle shaped, crystalline deposits with lengths varying from 400 to 1450 A and widths from 60 to 120 A. Selected area electron diffraction studies of the Michaelis-Guttmann bodies show a diffraction pattern consistent with the x-ray powder diffraction pattern for hydroxyapatite.