| Abstract|| |
A 44-year old man with xanthogranulomatous pyelonephritis presented with abdominal distention, left lumber pain, fever, loss of appetite, and loss of weight. He had been known to have diabetes mellitus type II for 20 years, and he was diagnosed to have a left renal stone three months prior to this presentation. The patient's urine and the left psous abscess grew staphylococcus aureus.
Keywords: Xanthogranulomatous pyelonephritis, Diabetic mellitus, Renal stone, Staphylococcus aureus
|How to cite this article:|
Al- Hwiesh AK. Xanthgranulomatous Pyelonephritis Associated with Staphylococcus Aureus. Saudi J Kidney Dis Transpl 2007;18:613-6
|How to cite this URL:|
Al- Hwiesh AK. Xanthgranulomatous Pyelonephritis Associated with Staphylococcus Aureus. Saudi J Kidney Dis Transpl [serial online] 2007 [cited 2020 Jun 2];18:613-6. Available from: http://www.sjkdt.org/text.asp?2007/18/4/613/36522
| Introduction|| |
Xanthogranulomatous pyelonephritis (XPN) is an unusual variant of chronic pyelonephritis that is complicated by urinary obstruction in two-thirds of the cases and associated with infected renal stone.,,,,, Affected patients usually have massive destruction of the kidney that requires nephroctomy. The inflammation rarely extends beyond the renal capsule to retro-peritoneal and adjacent tissue. The space-occupying nature and rapid expansion makes the differentiation between XPN and neoplasm difficult.  The coexistence of XPN and Staphylococcus aureus has been reported in few cases previously. Here we describe a case of XPN secondary to Staphylopcoccus aureus infection that extended beyond the renal capsule and was associated with diabetes mellitus and renal stone.
| Case Report|| |
A 44-year-old Saudi man was admitted to our hospital in July 2005 with complaint of abdominal distension and left lumber pain for 20 days prior to presentation. The patient had a known case of poorly controlled type II diabetes mellitus complicated by diabetic kidney disease and retinopathy.
The patient was apparently well until three months prior to admission when he developed frank hematurea, left lumber pain, dysurea, and frequency and urgency of urination. Intravenous pyelogram revealed a small renal stone in the left kidney. He required 10 days of antibiotics for the associated urinary tract infection. Two months later, the patient started to develop abdominal distension associated with intermittent colicky left lumber pain that increased with movement and lifting his left leg, interfered with his daily activities, and limited his ability to walk. These symptoms were accompanied with high grade fever, nausea, vomiting, profuse sweating, loss of appetite loss of weight, and constipation.
There was no history of contact with jaundiced patients or with birds or animal or patients with tuberculosis. The physical examination revealed a middle age man in pain but oriented to time, place, and person with BP 110/70 mmHg, pulse 120/min, respiratory rate 20/min, and temperature 39 o c. The lungs were clear for precaution and auscultation, and the cardiovascular system was unremarkable. The abdomen was distended with palpable 3x4 cm tender mass in the left abdominal region. The bowel sounds were within normal limits and the rectal exam was unremarkable. There was limited flexion of the left leg, decreased sensation on L3-L4 distribution, and a decrease of left knee reflex.
The initial clinical assessment was compatible with acute pyelonephritis with possible emphysematous pyelonephritis, xanthgranulomatous pyelonephritis, or malignancy.
The laboratory investigations revealed WBC 15.7x1000 /µL (neutrophils 90%), hemoglobin 90 g/L, platelets 455 x1000/ µL, BUN 16 mmol/L, creatinine 150 µmol/L, NA 125 mmol/L, K 4.5 mmol/L, Cl 90 mmol/L, CO2 21 mmol/L, Anion Gap 14, total bilirubin 0.3 mg/dl total protein 69 g/L, albumin 20 g/L, alkaline phosphates 233 U/L, SGOT 43 U/L, GTP 20 U/L, LDH 125 U/L,GGTP 184 U/L, and erythrocyte sedimentation rate 133 1 st hour. The urinalysis revealed cloudy urine with protein 1g/L leukocytes 3040 RBC 30-50 and bacteria +3. The urine culture grew staphylococcus aureus however, the blood culture was negative. Prothrombine time, partial thromboplastine time, calcium, phosphorus, magnesium, and uric acid were within normal. The tuberculin skin test (PPD), and urine for acid fast bacilli (AFB) early morning were negative three times. The kidney urinary bladder (KUB) x-ray was within normal limits. Abdominal ultrasound revealed a heterogeneously echoic lesion at the lower left psoas muscle and infiltrating the lower left renal pole. The computerized tomography (CT) of the abdomen confirmed the findings of the ultrasound [Figure - 1].
The patient received initially broad spectrum antibiotics that was adjusted later for Staphylococci aureus. Incision and drainage of the abdominal mass produced 400 ml of pure pus. [Figure - 2], discloses the lesion on CT of the abdomen after drainage. The renal biopsy was also performed [Figure - 3]. The microscopic examination of the XPN reveals inflammatory cells that are largely lipid-laden macrophages [Figure - 4].
| Discussion|| |
XPN often occurs in middle age women who frequently have history of recurrent urinary infection.  The typical presenting symptoms include flank pain, fever, malaise, anorexia and weight loss. A unilateral renal Mass is usually palpable on physical examination. Blood tests usually reveal nonspecific abnormalities that include anemia, increase in erythrocyte sedimentation rate, and impaired liver function tests. The urinalysis reveals pyuria and bacteruria. The urine culture demonstrates typically gram negative organisms ( Escherichia More Details coli, proteus, mirabilis, klebsiella and providencia); staphylococcus aureus is rarely involved. In our patient both the urine culture and the necrotic tissue culture grew staphylococcus aureus.
The diagnosis of XPN is confirmed by renal ultrasound and/or abdominal CT image. The gross examination of the affected kidney discloses an enlarged and destroyed kidney by the inflammatory process with necrotic yellow material surrounded by a layer of orange colored tissue, and staghorn calculi are usually present within the mass. On microscopic examination, the lesion comprises three layers centered by a calyx.  The inner zone consists of necrosis, leukocytes, lymphocytes, plasma cell, and macrophages. The middle zone contains vascularized granulation tissue interspersed with hemorrhage. The inflammatory cells are largely lipid-laden macrophages. Furthermore, the outermost part of the lesion is characterized by giant cell and cholesterol clefts. XPN is most frequently confused with renal carcinoma. The evidence of chronic urinary tract infection and the findings on abdominal CT scan usually allow this disorder to be distinguished from neoplasm. However, XPN and renal cell carcinoma can coexist. ,,,
The usual treatment of XPN is nephrectomy and IV antibiotic. However, in our patient, the XPN related to staphylococcus aureus was treated with abscess drainage and IV antibiotics, and the disease completely resolved.
| References|| |
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Abdulla K Al- Hwiesh
Department of Internal Medicine, King Fahd Hospital of the University, P.O. Box 40246, Al Khobar 31952
[Figure - 1], [Figure - 2], [Figure - 3], [Figure - 4]