title: Renal parenchymal malacoplakia: a different stage of xanthogranulomatous pyelonephritis?
abstract: Malacoplakia is a rare inflammatory condition characterized by demonstrative Michaelis-Gutmann bodies, which are foamy histiocytes with distinctive basophilic inclusions. Malacoplakia is caused by the inadequate elimination of bacteria by macrophages or monocytes as a result of defective phagocytic activity. Xanthogranulomatous pyelonephritis is characterized by the destruction of renal parenchyma and its replacement by solid sheets of foamy lipid-laden macrophages. Prolonged infection of the kidney, which is frequently caused by an obstruction of the urinary tract, is the pathologic mechanism of that condition. We present a 6-year-old patient with a poorly functioning kidney who had a prolonged recurrent urinary tract infection. The results of histologic analysis revealed an inflammatory infiltration consisting predominantly of foamy and epithelioid histiocytes that contained round intracytoplasmic concretions characteristic of Michaelis-Gutmann bodies. We suggest that malacoplakia might be a stage of xanthogranulomatous pyelonephritis.
authors.affiliation: Department of Pediatric Surgery, Baskent University Faculty of Medicine, 06490 Bahçelievler Ankara, Turkey.
authors.forename: Murat
authors.initials: M
authors.lastname: Yiğiter
authors.forename: Dilek
authors.initials: D
authors.lastname: Ilgici
authors.forename: Mustafa
authors.initials: M
authors.lastname: Celik
authors.forename: Irfan Serdar
authors.initials: IS
authors.lastname: Arda
authors.forename: Akgün
authors.initials: A
authors.lastname: Hiçsönmez
mesh_terms: D002648:Child; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007668:Kidney / Q000473:pathology* / Q000601:surgery; D008287:Malacoplakia / Q000175:diagnosis* / Q000601:surgery; D011705:Pyelonephritis, Xanthogranulomatous / Q000175:diagnosis* / Q000601:surgery