Malacoplakia

from Wikipedia, the free encyclopedia
Classification according to ICD-10
N28.8 Other specified diseases of the kidney and ureter
N32.8 Other specified diseases of the bladder
N36.8 Other specified diseases of the urethra
ICD-10 online (WHO version 2019)
Microphoto of malacoplakia with Michaelis Gutmann bodies ( HE staining )

As malacoplakia is called a rare chronic inflammatory disease associated with macroscopically visible plaque-like or tumor-shaped, white-gray deposits in the area of kidneys , ureters or bladder accompanied. Diffuse infiltration of the kidney parenchyma can also occur. The plaques arise mainly in the context of chronic urinary tract infections , mostly due to coli bacteria . Often there is also a weak immune system (immune deficiency) or a tumor disease . Other organs such as the gastrointestinal tract, lungs or skin are less commonly affected.

The histological correlate are large, polygonal shaped macrophages with foamy, eosinophilic cytoplasm ( von Hansemann cells) . Pathognomonic are PAS-positive , granular deposits (granules) , as Michaelis Gutmann bodies are called. It is assumed that the Michaelis Gutmann corpuscles represent the remains of phagosomes , which contain incompletely digested bacteria and deposits of calcium and iron . The underlying cell defect is likely the decreased ability to kill ingested bacteria.

Characteristic symptoms are high fever, flank pain and possibly a palpable tumor. Also, acute renal failure has been reported. A malignant tumor of the kidney or the lower urinary tract is often thought of first until the tissue examination proves the diagnosis.

The diagnosis of malacoplakia includes urine culture , blood culture , imaging diagnostics and cystoscopy with biopsy of the lesions. Malacoplakia is treated with long-term antibiosis or surgical rehabilitation.

Originally, the prognosis for malacoplakia with involvement of the renal parenchyma was very poor, the mortality was around 70%, and 90% of the survivors suffered permanent kidney damage . Since 1990, malacoplakia has preferably been treated with fluoroquinolones , antibiotics that penetrate cells particularly well. Since then, the prognosis of the disease has improved considerably, mortality has fallen below 10%, kidney function deteriorates in around 25%, and surgical rehabilitation is only required in rare cases. A prerequisite for a favorable course is the rapid histological confirmation of the diagnosis and the prompt start of antibiotic therapy.

literature

Web links