Focal xanthogranulomatous pyelonephritis presenting as renal tumor

Frozen Section Biopsy and Nephron-Sparing Surgery for a Multiloculated Cyst of the Kidney; Is this the Ideal Approach?

Multiloculated cystic renal masses are uncommon in the pediatric population. The presentation may be as an asymptomatic incidental finding on imaging, abdominal mass, abdominal pain, or urinary tract infection. The differentiation between benign and malignant causes of a cystic lesion by clinical and radiological examination is difficult. Tru-cut biopsy is not recommended due to fear of upgrading a malignant tumor. A definitive diagnosis is confirmed histopathologically only after surgery. Based on certain imaging characteristics, benign nature can be suspected and a conservative approach to surgery can be contemplated to save the kidney. Frozen section biopsy is useful in ruling out malignancy while doing nephron-sparing surgery (NSS) in these patients. NSS may be done by an open or minimally invasive approach. After histological confirmation of cystic nephroma, no other adjuvant treatment is necessary, but long-term surveillance is strongly recommended.

Nephron-sparing management of Xanthogranulomatous pyelonephritis presenting as spontaneous renal hemorrhage: a case report and literature review

Background

Xanthogranulomatous pyelonephritis (XGP) is an uncommon infectious disease of the kidney known to mimic other renal maladies. A rare presentation of this uncommon disease is spontaneous renal hemorrhage (SRH).

Case presentation

We report a case of XGP in a 58 year old woman who presented with abdominal pain, hematuria, and radiating left flank pain. CT scan was felt to be consistent with perirenal hemorrhage abutting a fat-containing renal mass. The patient was eventually taken to surgery for left partial nephrectomy. Pathology report returned as XGP, and the patient has no complications from this disease process at 8 month follow up.

Conclusion

Our search of the literature shows XGP presenting as SRH to be a rare clinical entity. Furthermore, this is the first such case managed with a nephron-sparing approach. The “great imitator” XGP should be added to the differential for patients presenting with spontaneous renal hemorrhage.

Case report: Xanthogranulomutous pyelonephritis presenting as "Wilms' tumor"

Background

Xanthogranulomatous pyelonephritis (XGP) is a rare renal tumor that arises as a complication of chronic obstructive pyelonephritis of uncertain etiology. It is primarily an adult tumor seen occasionally in children associated with urinary tract obstruction due to congenital urological anomalies, nephrolithiasis, and recurrent urinary tract infections. Radiologically, it may show neoplastic features such as those seen in common pediatric renal malignancies like wilms’ tumor and renal cell carcinoma. This overlap in radiological manifestation frequently leads to misdiagnosis and delay in appropriate intervention. We report a case of a 3 years old boy who presented with history of recurrent urinary tract infections and a left renal mass initially thought to be Wilms’ tumor.

Case presentation

We present a case of a 3 years old boy admitted to the Pediatric oncology unit at Muhimbli National Hospital in Dar es Salaam, Tanzania with one year history of recurrent fever and urinary tract infection signs and symptoms refractory to antibiotic therapy. He was eventually found to have a left kidney mass detected at the District hospital by abdominal ultrasound performed to evaluate a flank mass that was felt by his mother. He was then referred to our unit for a suspicion of Wilms’ tumor which finally turned out  to be a left kidney Xanthogranulomatous pyelonephritis.

He underwent a successful left nephrectomy and was discharged from hospital in a stable clinical condition and remains asymptomatic at the time of submission of this case report.

Conclusion

This case report underscores the need for clinicians attending a febrile child with a renal mass that can be confused with common pediatric renal malignancies such as Wilms’ tumor to broaden their differential diagnosis. The case also underlines the significance of individualized patient evaluation because this patient would have otherwise received preoperative chemotherapy under the International Society of Pediatric Oncology (SIOP) guidelines if the diagnosis of Wilms tumor was not ruled out.

A 13-Month-Old With Xanthogranulomatous Pyelonephritis With Features of Renal Malakoplakia

Xanthogranulomatous pyelonephritis is an uncommon chronic inflammatory renal disorder caused by chronic infection with gram-negative bacteria leading to destruction of the renal parenchyma and replacement with foamy lipid-laden macrophages. Renal malakoplakia is another rare form of chronic inflammatory granulomatous disease in the kidney associated with infection usually occurring in adults with immunocompromised status or debilitating disease. It is hallmarked by the finding of foamy histiocytes with distinctive basophilic inclusions (Michaelis-Gutmann bodies). We present a case of a 13-month-old male with history of congenital hydronephrosis who presented with clinical and radiologic findings suggestive of xanthogranulomatous pyelonephritis. However, further pathologic studies revealed the presence of Michaelis-Gutmann bodies, which are pathognomonic for renal malakoplakia. With this case we hope to bring further evidence to support that these two conditions are not mutually exclusive but rather represent two pathologic processes on the same disease spectrum.