Xanthogranulomatous Pyelonephritis Causing Renocolic Fistula Presenting as Symptomatic Anemia

Abstract

Renocolic fistula is a rare clinical finding that is most commonly iatrogenic after surgical intervention. Herein, we present a case of renocolic fistula secondary to xanthogranulomatous pyelonephritis (XGP) with a subtle presentation as anemia. A 40-year-old female was found to have a hemoglobin of 6.5 g/dL after presenting for worsening fatigue. A urinalysis was remarkable for numerous white blood cell (WBC), positive bacteria, and nitrite. As part of her anemia workup, an esophagogastroduodenoscopy (EGD) was done which was normal while a colonoscopy showed a fistula opening with surrounding nodularity close to the splenic flexure of the colon. A computed tomography (CT) scan of the abdomen and pelvis with contrast showed chronic left kidney pyelonephritis with multiple contiguous abscesses in the inferior left kidney in addition to a staghorn calculus concerning for XGP. The patient was started on antibiotics and underwent laparotomy with repair of the renocolic fistula, partial omentectomy, and left nephrectomy. She tolerated the surgery well and was discharged with a stable hemoglobin. XGP is a rare type of chronic pyelonephritis that is usually a result of chronic obstruction by an infected stone. Spontaneous renocolic fistulas are rare nowadays with the advancement in antibiotics and renal stones treatment.

A pediatric case of xanthogranulomatous pyelonephritis in the setting of Covid-19 and multi-system inflammatory syndrome (MIS-C)

“…An array of complications of XGP have been described which are often secondary to involvement of adjacent organs. In children, these complications include abscesses involving the psoas muscle [ [57] , [58] , [59] ] or perinephric spaces, fistulas including nephrocutaneous [ 60 , 61 ], nephroduodenal [ 62 ], nephrocolonic [ 25 , 61 , 63 ] and even nephrobronchial [ 64 ]. There have also been reports of concomitant liver lesions [ 65 ], bronchiectasis [ 66 ] and associated renal vein thrombosis [ 67 ].…”

Xanthogranulomatous Pyelonephritis: A Narrative Review with Current Perspectives on Diagnostic Imaging and Management, Including Interventional Radiology Techniques

“…The degree of extra-renal extension can be profound, with reported cases of pancreatic, splenic and hepatic infiltration with abscess formation, cutaneous, colonic and duodenal fistulae and rib osteomyelitis also described. [10][11][12][13][14][15] Very rare instances of renal amyloidosis secondary to XGP have been reported. 16-18.…”

“…Extra-renal extension including collections and fistulae are well depicted on CT, which permits demarcation of the extent and boundaries of the inflammatory process, determining if it is confined to the kidney (focal/segmental or disseminated) (Figure 5) and, in the presence of extrarenal extension, if it is confined to the perinephric or pararenal spaces and/or if it infiltrates adjacent tissues and viscera. [10][11][12][13][14][15] A case series of 11 patients with XGP found that 10 patients (91%) had extra-renal extension, three of whom (27%) had direct extension into adjacent structures including iliopsoas muscle, abdominal wall and spleen. 37 CT facilitates staging as per Malek et al as follows: 26 Stage 1: Confined to renal parenchyma.…”

“…Complications such as infiltration of the pancreas, spleen and liver with secondary abscess formation, cutaneous and colonic fistulae as well as rib osteomyelitis are all elegantly demonstrated by CT (Figure 6). [11][12][13][14][15] The main differential diagnosis for the CT appearances of XGP is primary renal malignancy; the presence of a Bear-Paw sign, a staghorn calculus and extrarenal extension of inflammation can help to differentiate XGP from primary renal malignancy. Although these are the characteristic imaging features of XGP, there is variability in their presence as described above; thus, while XGP may be the primary differential on CT, this often requires pathologic confirmation, given the significant overlap of findings with other conditions such as pyelonephritis, tuberculosis, malakoplakia and megalocytic interstitial nephritis.…”

A Rare Case of Xanthogranulomatous Pyelonephritis with Spontaneous Renocolic Fistula and IVC Thrombosis

“…Xanthogranulamatous pyelonephritis (XGPN) is a rare cause of chronic renal disease, characterized by suppuration and accumulation of lipid-laden macrophages in the renal parenchyma [ 1 ]. A really uncommon sequela is the renocolic fistula, which is usually a consequence of primary bowel pathologies [ 2 , 3 ].…”