Acute kidney injury secondary to obstructive bladder malakoplakia: a case report

BackgroundMalakoplakia is a rare granulomatous inflammatory condition that can affect immunosuppressed patients. The genitourinary system is the most involved organ. We present a case of kidney failure caused by obstructing bladder lesions, clinically suspicious for malignancy and pathologically proven to be malakoplakia.Case presentationA 70-year-old woman presented with acute kidney injury and Escherichia coli (E.coli) bacteremia. Investigation showed bilateral hydronephrosis with thickening of the renal pelvises suggestive of urothelial malignancy. Cystourethroscopy revealed multiple bladder lesions completely obliterating both ureteral orifices. Pathology of the resected lesions confirmed the diagnosis of malakoplakia. Patient was treated with a prolonged antibiotic course over 6 months with recovery of her kidney function.ConclusionMalakoplakia can mimic invasive tumors, and the diagnosis is only attained through histopathology which uniquely demonstrates the pathognomonic Michaelis-Gutmann inclusions inside sheets of histiocytes. Treatment is largely dependent on prolonged antibiotics therapy that must cover the most common isolated pathogen, E.coli.