[PP-252]
Patognomic ‘bear paw’ sign in the case of xanthogranulomatous pyelonephritis: Case report
Mehmet Erhan Aydın, Ertuğrul Şefik, Özgü Aydoğdu, İsmail Basmacı, Serdar Çelik, İbrahim Halil Bozkurt, Deniz Bolat, Tarık Yonguç, İbrahim Küçüktürkmen, Çetin DinçelINTRODUCTION: Xanthogranulomatous pyelonephritis (XGP) is an unusual variant of chronic pyelonephritis. Dilate calices and multiple low-density areas in renal parenchyma may be seen in computed tomography. These hypodense areas are debris-filled calyces and collections full of xanthe. The periphery of hypodense areas is enhanced due to increased vascularization and inflammation. Renal pelvis does not dilate due to the chronic inflammatory fibrosis. These areas are called "bear paw" because of their similarity. In this article, we aim to present the appearance of a bear paw sign that appears as a result of imaging when pyelonephritis and ureteric stones are examined.
CASE: A 60-year- old male patient was admitted to our clinic with complaints of frequent urinary tract infections, right side pain, and height fever.The patient had no operation history and no chronic disease. The patient had received antibiotics for urinary infections 4 times in the last 1 year. Physical examination revealed a 38 degree height fever and right costovertebral angle sensitivity. Laboratory values were 19.130 / mm3 for leukocyte and 1.8 mg / dl for creatinine. In urinanalysis, abundant leukocyte and nitrite positivity was seen.Escherichia coli was detected in urine culture and antibiotherapy was given.Urinary ultrasonography (USG) and abdomen BT performed on the patient revealed that grade 3 hydroureteronephrosis (HUN) in the right kidney and two ureteric stones, 6 and 3 mm, in the right ureterovesical (UV) junction. URS-L operation was performed for right ureter stones. During operation was seen that right UV junction was fibrotic and narrow. The ureter stones were broken by entering the right ureter and the DJ stent was inserted. The patient was discharged on the first postoperative day and after 8 weeks, the DJ stent was removed. After 5 months, the patient was referred to our clinic with similar complaints. Urinary USG and pre-post contrast- enhanced abdomen CT were performed and Grade 3 HUN, thinning of the parenchyma, dilation in the calyces, thickening of the right renal pelvis wall, bear paw sign (Figure 1), in right kidney and dilatation and tortuosity in the right ureter until UV, two lymphodenopathies (LAP) in the paracaval region 45x35 mm in size were seen. The ARB, which was observed 3 times in the urine, was negative to rule out urinary tuberculosis. Afterwards, the patient underwent right diagnostic URS. The advanced fibrotic stricture in the right UV junction was passed by the guide and the pyuria was seen in the right ureter.No other pathology was seen in the right ureter and right renal pelvis, and a DJ stent was inserted. Escherichia coli was reoccurred in urine culture obtained from the intraoperative right ureter and after antibiotherapy was completed, the patient was discharged. After 3 months of follow-up,abdomen BT was performed and pathologic findings in the right kidney were regressed and there was no LAP in the paracaval region. The patient was followed up.
CONCLUSION: Radiologic imaging is very important for urological diagnosis. 'Bear paw’ sign may be an informative finding in the evaluation of xanthogranulamatous pyelonephritis.
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Bear paw sign in the right kidney, CT