Renal malacoplakia with papillary necrosis and renal failure

[Renal malakoplakia: an underestimate cause of renal failure]

Malakoplakia is an inflammatory granulomatous disease induced by defective phagocytic activity of macrophage. Malakoplakia is histologically characterized by the presence of Michaelis-Gutmann bodies in macrophages. Although not uncommon in the genito-urinary tract, isolated malakoplakia of the kidney is rarely found. Its main clinical presentation associates acute renal failure and acute pyelonephritis. The clue for diagnosis of renal malakoplakia is based on renal biopsy showing Michaelis-Gutmann bodies. Establishing the diagnosis of renal malakoplakia is essential as it determines the choice of antibiotics and duration of treatment. Prognosis remains poor, leading frequently to chronic renal failure. In this paper, we report four cases of renal malakoplakia and discuss clinical presentation, biological and pathological features, treatment and prognosis of this disease.

Renal parenchymal malacoplakia: a rare cause of ARF with a review of recent literature

Renal parenchymal malacoplakia is a rare cause of acute renal failure. Traditionally, it was associated with a high mortality rate and commonly resulted in renal failure requiring renal replacement therapy. The authors report on a 70-year-old woman who presented with acute renal failure caused by renal parenchymal malacoplakia. Her renal function recovered after levofloxacin treatment. All cases reported in the English-language literature since 1990, when fluoroquinolone was first used to treat malacoplakia, were reviewed. Although some patients still had renal failure, with renal biopsy and fluoroquinolone treatment, the patient mortality rate from renal parenchymal malacoplakia is remarkably low.

Sonographic findings in renal parenchymal malacoplakia

Malacoplakia of the kidney is a rare inflammatory disorder. We describe a case of bilateral renal malacoplakia in which the patient had diffuse involvement of the left kidney and a focal lesion in the right kidney. Sonography showed a diffusely echogenic, enlarged left kidney with loss of corticomedullary differentiation and a single anechoic lesion measuring 1.8 x 1.6 x 1.3 cm in the right kidney. A left nephrectomy was performed, and the right kidney was managed conservatively with sonographic monitoring.

Renal malacoplakia with secondary hepato-duodenal involvement

Renal parenchymal malacoplakia is uncommon, and coexistence of extensive invasion into the liver and duodenum is extremely rare. Typically, there is an associated long-term urinary tract infection. We report on a 53-year-old woman with a history of diabetes and recurring pyelonephritis, who presented with a renal tumor and upper gastrointestinal bleeding. Surgical intervention included radical nephrectomy, lymphadenectomy, segmental hepatectomy, cholecystostomy, duodenorrhaphy, jejunostomy and appendectomy. There was no surgical morbidity. A pathologist confirmed the diagnosis of malacoplakia. All of the diagnostic criteria, including hematoxylin and eosin stain, iron stain, calcium stain and electron microscopy of Michaelis-Gutmann bodies, were classic. The literature is reviewed.

Renal malacoplakia reappraised

Renal malacoplakia is an unusual form of chronic tubulointerstitial nephritis with a predilection for patients with recurrent urinary tract infections and an immunocompromised state. Its characteristic feature is the parenchymal infiltration by macrophages with ample cytoplasm containing abundant periodic acid-Schiff-positive granules, known as von Hansemann cells, and the presence of diagnostic extracytoplasmic or intracytoplasmic calcospherites, known as Michaelis-Gutmann bodies. Renal malacoplakia is more common in women (female to male ratio 3:1), in whom the lesions develop in a younger age group (third to fifth decade) than in men (over 50 years). Enlarged kidneys in the presence of persistent urinary infection should lead to the consideration of this entity. The diagnosis can only be established by pathologic examination of renal tissue. Renal biopsy early in the course of the disease is essential since in an increasing number of cases medical therapy has resulted in resolution of the disease process and preservation of renal function.