Malacoplakia of the urinary tract is an uncommon chronic granulomatous inflammatory disease of the bladder wall. Malakoplakia (meaning "soft plaque") can affect any organ, but the urinary bladder is the most common location.
Malacoplakia has a peak incidence in middle age and has a reported female-to-male ratio of 4:1 1. Other risk factors include immunosuppression, AIDs and diabetes mellitus.
Presenting symptoms include gross hematuria, lower urinary tract symptoms and recurrent urinary tract infection (most commonly with Escherichia coli ). Papules, plaques and ulceration on direct visualization during flexible cystoscopy have been described 5.
Although infection with E. coli is very often observed, impaired host bactericidal defenses and defective phagocytosis are considered an important part of the pathogenesis 1.
Von Hansemann cells (ovoid histiocytes) which contain Michaelis-Gutmann bodies are a histologic hallmark 2,5. Identification may require special stains.
Within the urinary tract, the bladder is the most frequently affected organ (40% of patients with malacoplakia).
Imaging characteristics of malacoplakia are varied, and most commonly observed within the bladder, although plaques may also occur in the ureters.
Malacoplakia may present as multiple, polypoid, vascular, solid masses or as circumferential wall thickening, associated with vesicoureteral reflux and dilatation of the upper urinary tract. These masses vary in size from a few millimeters to several centimeters. Occasionally, malacoplakia can be locally aggressive and invades surrounding structures even causing bone erosions 1.
Treatment and prognosis
Although malacoplakia may be extremely aggressive, invading the perivesical space, and it can even cause bone destruction, non-surgical medical management is the mainstay of treatment, and as such, biopsy for accurate diagnosis is essential.
Treatment regimens include antibiotics, ascorbic acid, and a cholinergic agonist 1.
History and etymology
The term derives from "μαλακία" (malakia: "soft") and "μαλακία" (plakia: "slab/plaque").
The terms "malaco"plakia and "malako"plakia are used interchangeably as latinisations of "μαλακία".
The term was first used by Von Hansseman, but the condition was first described by Michaelis and Gutmann in 1902 1.
- transitional cell carcinoma
- multifocal or long-segment strictures
- calcification is commonly seen
- squamous metaplasia of the urothelium
- more common in bladder
- reactive proliferative changes of the urothelium causing multiple small subepithelial cysts
- 1. Michaelis L & Gutmann D. Ueber Einschlüsse in Blasentumoren. Zeitschrift für klinische Medizin 1902;47:208
- 2.Wong-you-cheong JJ, Woodward PJ, Manning MA et-al. From the archives of the AFIP: Inflammatory and nonneoplastic bladder masses: radiologic-pathologic correlation. Radiographics. 26 (6): 1847-68. doi:10.1148/rg.266065126 - Pubmed citation
- 3. Haaga JR, Boll D. CT and MRI of the whole body. Mosby. (2009) ISBN:0323053750. Read it at Google Books - Find it at Amazon
- 4. Dasgupta P, Womack C, Turner AG et-al. Malacoplakia: von Hansemann's disease. BJU Int. 1999;84 (4): 464-9. Pubmed citation
- 5. Dong H, Dawes S, Philip J, Chaudhri S, Subramonian K. Malakoplakia of the Urogenital Tract. (2015) Urology case reports. 3 (1): 6-8. doi:10.1016/j.eucr.2014.10.002 - Pubmed