Idiopathic segmental ureteritis, misdiagnosed as ureteral cancer preoperatively: A case report with literature review

A case of ureteral stenosis due to ureteritis probably associated with rheumatoid arthritis

Ureteritis associated with the immunological disorder is rarely reported, and most cases in this category are small vessel vasculitis and immunoglobulin G4-related disease. Rheumatoid arthritis (RA)-associated ureteritis is uncommon, and underlying aetiology is unclear. We present a patient with ureteritis who had a medical history of RA and was successfully treated with steroids and immunosuppressant. A 49-year-old woman who had been treated for RA and atopic dermatitis suffered from gross haematuria for 5 successive days. Contrast-enhanced computed tomography (CT) showed right-dominant upper urinary tract dilatation with enhanced thickened wall. The haematuria continued accompanied with intermittent right back and lower abdominal pain, and the following CT image taken after 3 months presented the progression to bilateral hydronephrosis. Ureteral stents were placed, and antibiotic therapy was introduced for obstructive pyelonephritis. Ureterocystoscopy and following biopsy from the upper ureteral tract showed a chronic inflammatory change in the histopathology, and we finally considered the stenosing ureteritis to be caused by immune-mediated mechanism related to RA. After starting steroid therapy with methotrexate, therapeutic response was obtained to remove the stents. In the cases of ureteritis or ureteral stenosis of unknown aetiology with a medical history of immunological disorders, we should consider the underlying immune-activated state and try to test contrast-enhanced CT and histological examination before performing a surgical procedure. After excluding the common causes of ureteritis or ureteral stenosis, these tests would support the appropriate diagnosis.

A case of IgG4-related interstitial nephritis with ureteral obstruction: case report and literature review

BACKGROUND

IgG4-related disease (IgG4-RD) is a newly discovered systemic disease that can affect any organ or tissue in the body. IgG4-related kidney disease (IgG4-RKD) is relatively rare but essential to IgG4-RD. However, there are few reports of IgG4-RD mimicking malignant ureteral tumors leading to hydronephrosis. We report here a rare case of IgG4-RD involving the ureter.

CASE PRESENTATION

An 87-year-old man presented to our nephrology department with anorexia, nausea, and acute kidney injury in November 2020. Urinary computed tomography (CT) examination revealed a right lower ureter mass with right renal and ureter hydronephrosis. The serum level of IgG4 was 1890 mg/dL, and the concurrently renal biopsy revealed extensive infiltration of IgG4-positive plasma cells in renal interstitium, which was diagnosed as IgG4-associated tubule-interstitial nephritis(IgG4-TIN). The renal function improved significantly after double-J tube implantation of the right ureter and moderate-dose hormone therapy. The serum IgG4 decreased to the normal range, and the right lower ureter mass almost disappeared after one year of low-dose hormone maintenance therapy.

CONCLUSION

IgG4-RD can present as a mass in the renal pelvis and (or) ureter, leading to hydronephrosis. Therefore, early recognition of this disease is significant. Most patients respond well to hormonal therapy to avoid surgical treatment due to misdiagnosis as malignant tumors, causing secondary harm to patients.

Hydronephrosis with ureteritis developed in C57BL/6N mice carrying the congenic region derived from MRL/MpJ-type chromosome 11

Inbred MRL/MpJ mice show several unique phenotypes in tissue regeneration processes and the urogenital and immune systems. Clarifying the genetic and molecular bases of these phenotypes requires the analysis of their genetic susceptibility locus. Herein, hydronephrosis development was incidentally observed in MRL/MpJ-derived chromosome 11 (D11Mit21-212)-carrying C57BL/6N-based congenic mice, which developed bilateral or unilateral hydronephrosis in both males and females with 23.5% and 12.5% prevalence, respectively. Histopathologically, papillary malformations of the transitional epithelium in the pelvic-ureteric junction seemed to constrict the ureter luminal entrance. Characteristically, eosinophilic crystals were observed in the lumen of diseased ureters. These ureters were surrounded by infiltrating cells mainly composed of numerous CD3⁺T-cells and B220⁺B-cells. Furthermore, several Iba-1⁺macrophages, Gr-1⁺granulocytes, mast cells and chitinase 3-like 3/Ym1 (an important inflammatory lectin)-positive cells were detected. Eosinophils also accumulated to these lesions in diseased ureters. Some B6.MRL-(D11Mit21-D11Mit212) mice had duplicated ureters. We determined >100 single nucleotide variants between C57BL/6N- and MRL/MpJ-type chromosome 11 congenic regions, which were associated with nonsynonymous substitution, frameshift or stopgain of coding proteins. In conclusion, B6.MRL-(D11Mit21-D11Mit212) mice spontaneously developed hydronephrosis due to obstructive uropathy with inflammation. Thus, this mouse line would be useful for molecular pathological analysis of obstructive uropathy in experimental medicine.

Routine diagnostic ureteroscopy for suspected upper tract transitional-cell carcinoma

BACKGROUND AND PURPOSE

Upper tract transitional-cell carcinoma (utTCC) is uncommon. Standard evaluation includes imaging, cytology, and cystoscopy and gold standard treatment is nephroureterectomy (NU) with solid oncologic outcomes and elevated morbidity. In this study, we report on the value of including routine ureteroscopy (URS) for evaluating suspected utTCC in shifting the treatment toward less morbid options and increasing preoperative diagnostic accuracy.

PATIENTS AND METHODS

Records of patients presenting between 2002 and 2013 with suspected utTCC were reviewed. Since 2010, URS has been included routinely in the evaluation protocol. Demographic, clinical, and pathologic characteristics were recorded and compared between earlier experience (group 1) and with routine URS (group 2). In addition, the number needed to treat (NNT) was calculated with respect to shifting the procedure choice from NU to other options as well as in reducing the rates of misdiagnoses.

RESULTS

A total of 118 patients were included: 63 in group 1 and 55 in group 2. The pathology-confirmed TCC rates were comparable between the two groups (78 vs 85%). The rates of NU decreased with routine URS use from 89% to 69% (P=0.011, NNT=5.05) whereby patients were treated endoscopically or with distal ureterectomy. Misdiagnoses decreased from 15.5% to 2.1% with routine URS (P=0.021, NNT=7.44). Sepsis occurred in two patients after URS.

CONCLUSIONS

In this initial study, routine URS evaluation for suspected utTCC appears to enable an increased use of other treatment choices rather then NU, with an estimated five URS avoiding one NU. Moreover, routine URS reduced the rates of misdiagnosis of TCC. Complications associated with URS may add an additional morbidity burden, however.

IgG4-related disease of the ureter: report of two cases and review of the literature

IgG4-related disease (IgG4-RD) is a recently recognized multi-organ fibro-inflammatory lesion characterized by elevated IgG4 serum levels and mass-forming lesions. This condition shows similar histological features independently of the site of origin including storiform fibrosis, obliterative phlebitis, and dense lymphoplasmacytic infiltrate with a conspicuous IgG4-positive plasma cell component. Since this disease has only recently been categorized as a single specific nosologic entity, lesions with these typical morphological features have previously been named in different ways, creating some confusion and making it difficult to identify cases published in the literature. Lesions with features suggesting IgG4-RDs have very rarely been reported in the ureter, and they have been named using the terms "inflammatory pseudotumor" and "idiopathic segmental ureteritis." Herein, we describe the clinicopathological features of ureteral IgG4-RD found in two different patients. An 82-year-old female and a 77-year-old male underwent ureteral resection due to severe ureteral wall thickness and lumen stenosis suggestive of urothelial carcinoma. However, histological examinations showed transmural fibro-inflammatory lesions, with abundant IgG4 plasma cells intermixed with histiocytes, lymphocytes, fibroblasts, and scattered eosinophils. We have also accurately reviewed the literature in order to identify, among lesions diagnosed with different names, examples of ureteral IgG4-related lesions to give the reader a comprehensive overview of this relatively rare inflammatory disease. We suggest using the name "ureteral IgG4-RD" for those lesions showing the same morphological features as IgG4-RDs located elsewhere.

First report of idiopathic segmental ureteritis successfully treated by steroid therapy

We report a case of bilateral idiopathic segmental ureteritis in a 52-year-old woman. The diagnosis was established by imaging studies (magnetic resonance imaging/computed tomography scan), ureteroscopy and biopsies. The left side improved spontaneously, but the right ureteral stricture persisted after 3 months of ureteral stenting. Administration of prednisolone effectively relieved obstruction on the right side after 4 months. This is the first report of idiopathic segmental ureteritis successfully treated by steroid therapy, without invasive open procedures.

Molecular pathology of murine ureteritis causing obstructive uropathy with hydronephrosis

Primary causes of urinary tract obstruction that induces urine retention and results in hydronephrosis include uroliths, inflammation, and tumors. In this study, we analyzed the molecular pathology of ureteritis causing hydronephrosis in laboratory rodents.F2 progenies of C57BL/6 and DBA/2 mice were studied histopathologically and by comprehensive gene expression analysis of their ureters. Incidence of hydronephrosis was approximately 5% in F2 progenies. Histopathologically, this hydronephrosis was caused by stenosis of the proximal ureter, which showed fibrosis and papillary malformations of the proliferative epithelium with infiltrations of B-cell-dominated lymphocytes. Additionally, CD16-positive large granular leukocytes and eosinophils infiltrated from the ureteral mucosa to the muscular layer. Eosinophilic crystals were characteristically observed in the lumen of the ureter and the cytoplasm of large granular leukocytes, eosinophils, and transitional epithelial cells. Comprehensive gene profiling revealed remarkably elevated expression of genes associated with hyperimmune responses through activation of B cells in diseased ureters. Furthermore, diseased ureters showed dramatically higher gene expression of chitinase 3-like 3, known as Ym1, which is associated with formation both of adenomas in the transitional epithelium and of eosinophilic crystals in inflammatory conditions. The Ym1 protein was mainly localized to the cytoplasm of the transitional epithelium, infiltrated cells, and eosinophilic crystals in diseased ureters.We determined that the primary cause of hydronephrosis in F2 mice was ureteritis mediated by the local hyperimmune response with malformation of the transitional epithelium. Our data provide a novel molecular pathogenesis for elucidating causes of aseptic inflammation in human upper urinary tracts.