Malakoplakia of Bladder

Malakoplakia of the bladder in a 60 y/o female with urinary frequency, dysuria, and hematuria. Cystoscopy showed numerous plaque-like lesions throughout the bladder. Malakoplakia is an unusual pattern of inflammatory response secondary to defective phagocytic function of macrophages. Bladder is one of the most commonly affected organs. The setting is usually chronic cystitis caused by E.coli or Proteus species. Macrophages become engorged with undigested bacterial debris. They are referred to as von Hansemann cells and have abundant foamy cytoplasm as seen in this image.