Xanthogranulomatous pyelonephritis

Introduction to yellow granulomatous pyelonephritis Xanthogranulomatous Pyelonephritis (XGPN) is a rare, severe chronic kidney inflammation that produces diffuse renal parenchymal destruction. basic knowledge The proportion of illness: 0.002% Susceptible people: no specific population Mode of infection: non-infectious Complications: Hypertension Obstructive nephropathy

Causes of yellow granulomatous pyelonephritis

Bacterial infection (55%):

Long-term chronic inflammation leads to continuous destruction of renal tissue, release of lipids, phagocytosis by tissue cells to form yellow tumor cells, and urinary tract obstruction combined with infection.

Body factor (45%):

Abnormal lipid metabolism, immune dysfunction, especially focal yellow granulomatous pyelonephritis due to low host immune function, so that mild inflammatory lesions in the renal parenchyma can not heal, Proteus, Escherichia coli is the most common Pathogenic bacteria, penicillin-resistant Staphylococcus aureus can also be caused.

Pathogenesis

Although it is certain that the disease is caused by bacterial infection and urinary tract obstruction can promote its occurrence, the pathogenesis is still unclear.

There are two types of pathological manifestations:

1 focal type: less common, mainly manifested as a yellow tumor-like mass in the kidney.

2 diffuse type: the kidney is obviously enlarged, most of them are pus and kidney, the renal parenchyma is severely damaged, and the tumor of the kidney can be seen on the surface of the renal pelvis or renal parenchyma. The lesion can be extended to the perirenal and extrarenal tissues. The peri-renal adhesions are extensively fibrotic and involve surrounding tissues and organs.

Malek clinical stage: stage I intrarenal: lesions are confined to the renal parenchyma, only invade 1 renal pelvis or part of the renal parenchyma; stage II renal cycle: intrarenal lesions with stage I, but have penetrated the renal parenchyma to invade the perirenal fat; Stage III renal stage: The lesion is diffuse in most or all of the kidneys and extensively affects the surrounding tissues of the kidney and the posterior peritoneum.

Microscopically, the orange-yellow lesions are composed of inflammatory tissues, which are composed of large foam macrophages, cytoplasmic granules of small macrophages, neutrophils, lymphocytes, plasma cells and fibroblasts, and a large number of periorbital mucosa. The neutrophils and necrotic tissue fragments, occasionally visible foreign body giant cells, the cytoplasm of foam macrophages, especially the cytoplasmic cells of granule small macrophages, were strongly positive for cytosolic PAS staining.

Yellow granulomatous pyelonephritis prevention

The main measures for prevention of this disease are as follows:

1. Insist on drinking more water every day, urinating frequently to flush the bladder and urethra, and avoid bacteria in the urinary tract. This is the easiest and most effective measure.

2. Pay attention to the cleansing of the genitals to reduce the bacterial flora in the urethra. If necessary, apply neomycin or furanodine cream to the mucosa or perineal skin of the urethra to reduce the on-site re-infection.

3. Try to avoid using urinary tract equipment and strictly aseptically operate if necessary.

Yellow granulomatous pyelonephritis complications Complications, obstructive nephropathy

The main complications are high blood pressure, obstructive nephropathy, urinary calculi and so on.

Yellow granulomatous pyelonephritis symptoms common symptoms fatigue and weight loss constipation irregular fever anorexia granulomatosis hypertension urinary tract infection kidney involvement

The disease is rare in clinical practice, often only unilateral kidney involvement, rare bilateral lesions; most patients with renal pain and recurrent urinary tract infections, fever (irregular fever), discomfort, fatigue, anorexia, weight loss, weight loss And constipation, from clinical manifestation to diagnosis, usually 3 months to 9 years, 73% of patients have stones, urinary tract obstruction or diabetes history, 38% have a history of urinary tract infection, 60% can reach the waist mass, 40% Have high blood pressure performance.

Examination of yellow granulomatous pyelonephritis

Urinary bacteriological examination

Urine examination of more than 88% of patients with pyuria and proteinuria; urine culture positive rate of 74% to 86%, mostly Escherichia coli and Proteus, occasionally penicillin-resistant Staphylococcus aureus, morning urine centrifugation, sediment The smear can be used to find foam cells. If there are more than 5 foam cells on a slice, the disease can be diagnosed, and the positive rate is 82.6%.

2. Blood test

Common white blood cells increase and erythrocyte sedimentation rate; anemia is more common, accounting for 65% to 78%.

3. Imaging examination

(1) X-ray examination: the X-ray changes of the disease are very inconsistent, various focal or diffuse lesions are visible, and depending on the presence or absence of obstruction, stones and other abnormalities, 80% of patients with IVP can It is found that the diseased kidney with stones is not developed, and the renal pelvis deformation is also common, especially the diseased kidney is diffuse, and the focal injury is characterized by a cystic or mass cavity, in which the filling defect.

Renal angiography showed that most of the yellow granulomatous nephropathy areas had reduced or absent blood vessels, and there were no intravascular small arteries without peripheral blood vessels, often without pathological blood vessels, and occasionally some cases showed increased blood vessels.

(2) CT examination: because of renal angiography alone, it is not possible to distinguish XGPN, avascular anomalous mass or necrotizing avascular adenocarcinoma, and CT scan can clearly show multiple nodules in the kidney or Large masses of low-density lesions with calculi and calcifications of the renal pelvis or collecting duct system. The restricted XGPN still has the following signs:

1 The kidney is enlarged and deformed, and there is a cystic density zone. The CT value ranges from -15 to 30 Hu, depending on the amount of lipid, but it does not show true fat density. After injection, it shows obvious enhancement of the periphery of the lesion. It is caused by the granulation tissue surrounding the multi-vessels, and the lipid-containing yellow tumor lesions are not enhanced.

2 localized renal mass, beyond the outline of the kidney, equal density or slightly higher density, resembles kidney cancer, but the enhancement is not obvious after enhancement. Because the surrounding renal parenchyma is obviously strengthened, the boundary of the lesion becomes very clear, and the relative density is low. This is different from kidney cancer.

3 The limited lesion morphology is mostly round, which reflects the slow growth of the lesion.

4 easy to invade the perirenal space and psoas muscle, CT showed thickening of the renal fascia, lesions and psoas muscle adhesions.

4. Renal histopathology

(1) Visual observation: visible renal enlargement, thickening and adhesion of renal capsule and perirenal tissue, lesions can be presented as a single tumor-like lesion confined to the kidney level, can also be diffuse multiple lesions, cutaway view, The renal pelvis and renal pelvis are dilated, containing pus-like fluids and/or stones (often staghorn). The renal parenchyma, especially the surrounding tissue of the dilated renal pelvis, is replaced by orange-yellow, soft inflammatory tissue. There are often multiple small abscesses around. Wrap around.

(2) The destruction of renal tissue under the microscope, the orange-yellow lesion tissue is composed of inflammatory large foam macrophages, small macrophages containing granular cytoplasm, neutrophils, lymphocytes, plasma cells and fibroblasts. Cells, etc., a large number of neutrophils and necrotic debris can be seen around the renal pelvis mucosa, even foreign bodies giant cells, cytoplasm of foam cells, especially small particles of mononuclear cells, PAS staining is strongly positive.

5. Magnetic resonance (MRI) and B-ultrasound are also helpful in diagnosis.

Diagnosis and diagnosis of yellow granulomatous pyelonephritis

Diagnostic criteria

The diagnosis of yellow granulomatous pyelonephritis is based on the possibility of XGPN in patients with chronic urinary tract infection, positive morning smear smear foam cells and X-ray findings of some suspicious lesions. X-ray changes include Unilateral renal enlargement, intravenous pyelography (IVP) showed no function of kidney, kidney and (or) ureter to find stones, angiography showed no vascular mass or a tumor with a thinning of the renal blood vessels, the blood vessels around the ureter were significant Cystic dilatation lesions, irregular renal lesions with significant renal impairment in significant avascular areas, and characteristic findings of CT and MRI values, according to which characteristics, 40% of cases can be diagnosed or preoperatively Diagnosis, in addition, because yellow granulomatous pyelonephritis is caused by bacterial infection, urine culture is almost always positive, and Proteus mirabilis and Escherichia coli are the most common, because Escherichia coli infection rate is high, resistant to penicillin I A similar situation is seen in the S. aureus infection.

Differential diagnosis

The disease is easily misdiagnosed as renal cell carcinoma. It has also been reported that this disease can be accompanied by renal cell carcinoma or transitional epithelial cancer. It should be noted that kidney cancer is a tumor rich in blood vessels, which can show obvious irregular enhancement. The disease is not enhanced, or there is peripheral enhancement. There is a sac-like or septal unenhanced area in the lesion. Therefore, enhanced scanning can provide an important basis for differential diagnosis. In addition, the disease has stones, obstruction, abscess and abscess. The substance and local yellow tissue adhere to the renal pelvis and renal pelvis, which is also an inflammatory disease, so it should be distinguished from other obstructive diseases such as chronic urinary tract infections such as renal tuberculosis.

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