Bladder Malacoplakia in a Patient on Chronic Hemodialysis Waiting for Kidney Transplantation

Dr. Athanase Billis, Departamento de Anatomia Patológica (HC), Faculdade de Ciências Médicas-UNICAMP, Caixa Postal 6111, CEP 13081-970 Campinas, SP (Brazil) in outline. A striking finding was the variability of the matrix of the phagolysosomes which contained: (1) microvesicles; (2) dark structures of a round or ovoid outline, some of them appearing indistinct or disintegrating; (3) myelin figures; (4) whorls and loops of trilaminated structures in a so-called ‘fingerprint’ pattern and (5) microcrystals. The latter were particularly seen in larger structures with matrix constituents identical to the Dear Sir, There are some case reports of malacoplakia following renal transplantation [1-6] but none diagnosed before transplantation. We had the opportunity to see a case of malacoplakia of the bladder in a 27-year-old female on chronic hemodialysis due to end-stage renal disease. The patient started a work-up for kidney transplantation. A cystourethrogram showed vesicoureteral reflux, and during cys-toscopy, some yellow patches which were biopsied were seen mostly in the trigone. The biopsy specimen was processed for light and electron microscopy. For light microscopy, the tissue was placed in 10% buffered formalin and embedded in paraffin. Sections, 5-μm thick, were cut and stained with HE, periodic acid-Schiff (PAS), von Kossa’s and Perl’s stains. For electron microscopy, the tissue was fixed in Karnovsky and embedded in Araldite. Thick sections for survey were stained with toluidine blue, and thin sections were cut and placed on grids for electron-microscopic evaluation. The ultra-thin sections were examined in a Carl Zeiss EM-10 electron microscope. On light microscopy, the surface epithelium was unremarkable. No ulcerations were seen. In the lamina propria of the mucosa, a dense and diffuse infiltrate of macrophages with rare scattered lymphocytes, plasmocytes and other inflammatory cells were seen. Large granules entirely filling the cytoplasm of the macrophages were strongly positive with the PAS reaction. Small spherules consistent with Michaelis-Gutmann bodies were frequently seen intraand extracellularly. These bodies were positive for iron (Perl’s stain) and calcium (von Kossa’s stain). Ultrastructural examination revealed macrophages containing numerous intracy-toplasmic phagolysosomes generally circular 7⁄87⁄8s1⁄8í7⁄8’l ïV·v í3⁄8 V.’·i7⁄8v.· < 4 ;’i.1’.;:·’V::’..”“:;3⁄8:’’ .■?:..;■■■ f3⁄8