Morphogenesis of Michaelis-Gutmann bodies in cerebral malacoplakia. An ultrastructural study.
Malacoplakia was found in the brain biopsy specimen from the wall of a cystic lesion in a 4-month-old girl. Ultrastructural study of the Michaelis-Gutmann bodies revealed that the initial stage of calcification appeared to be the deposit of needle-shaped apatite crystals within intracytoplasmic membrane-bound vesicles of histiocytes. Accumulation of apatite crystals and coalescense of calcified vesicles resulted in the formation of large laminated calcospherules. Extracellular Michaelis-Gutmann bodies and apatite crystal-containing matrix vesicles were also noted. Calcified vesicles and the Michaelis-Gutmann bodies were not observed in the phagolysosomes. Bacteria and viral particles were not identified. These findings suggest that matrix and intracytoplasmic membrane-bound vesicles play an important role in the initial stage of the formation of Michaelis-Gutmann bodies and that a mechanism other than bacterial or viral infection may be involved in cerebral malacoplakia.
Department of Pathology, Henry Ford Hospital, Detroit, MI 48202.
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D001031:Apatites / Q000378:metabolism; D001921:Brain / Q000378:metabolism / Q000473:pathology / Q000648:ultrastructure*; D001927:Brain Diseases / Q000378:metabolism / Q000473:pathology*; D003460:Crystallization; D003593:Cytoplasm / Q000648:ultrastructure; D005260:Female; D006644:Histiocytes / Q000378:metabolism / Q000648:ultrastructure; D006801:Humans; D007223:Infant; D008287:Malacoplakia / Q000378:metabolism / Q000473:pathology*; D008854:Microscopy, Electron
D001031:Apatites