Xanthogranulomatous cystitis and bilateral ureteral reflux due to bladder neck obstruction: a case report

Abstract

Xanthogranulomatous cystitis (XC) is a rare benign disease of chronic granulomatous inflammation. We report a 23-year-old woman with xanthogranulomatous cystitis. She was referred to our hospital with the chief complaint of a 1-year history of frequent, urgent dysuria with recurrent fever. An imaging examination showed bilateral ureteral reflux and a normal bladder. Urodynamic findings suggested bladder outlet obstruction and increased post-void residual urine. Finally, the patient underwent endoscopy, and bladder neck obstruction was confirmed. Additionally, we found multiple granulomatous masses in the bladder. Therefore, we performed transurethral resection of the tumor and bladder neck. A histopathological examination of resected tumor tissue showed xanthogranulomatous cystitis, and the patient received anti-infective therapy. Follow-up cystourethroscopic results and urination symptoms returned to normal, and the bilateral ureteral reflux was gradually reduced.

Introduction

Xanthogranulomatous inflammation, which is a type of chronic inflammation, typically occurs in the digestive system, such as the colon, appendix, salivary glands, and pancreas, and in the kidneys.^1,2 Xanthogranulomatous inflammation is also found in many other sites, including the brain, ovaries, and endometrium. However, xanthogranulomatous cystitis (XC) is extremely rare, and its etiology is unclear. Most cases of XC can be found during imaging examinations. Repeated urinary tract infections and long-term urinary retention may be the ultimate cause of XC.

We report a patient with urination symptoms, increased post-void residual urine, and bilateral ureteral reflux. We performed endoscopy and found many disorders in the bladder, such as bladder neck obstruction and multiple granulomatous masses. Finally, histopathology confirmed bladder outlet obstruction (BOO). We discuss the possible pathogenesis of XC in this unusual case and also emphasize the importance of endoscopy for repeated urinary tract infections.

Case report

A 23-year-old woman was referred to our hospital with the chief complaint of a 1-year history of frequent, urgent dysuria and lower abdominal discomfort with a repeated fever. The highest temperature during fever was 38.5°C, and it was accompanied by bilateral back pain. The patient’s symptoms were relieved after anti-infective treatment.

There was no history of hematuria or tuberculosis. The results of laboratory studies, including a white blood cell count and renal function tests, were within normal limits. A urine test showed a white blood cell count of 342/µL, and a urine bacterial culture showed infection with Escherichia coli. Tuberculosis-related examinations and chest X-rays were negative.

Ultrasound and enhanced computed tomography (CT) of the abdomen and pelvis showed bilateral hydronephrosis and ureteral dilation. The wall and capacity of the bladder were normal (Figure 1). A urodynamic examination showed a maximum urine flow rate of 19.3 mL/s, a high post-void residual urine volume of 130 mL, and the detrusor pressure at the maximum urine flow rate was >25 cmH₂O. However, these indicators were not sufficient to diagnose the patient with BOO.

Figure 1.

Enhanced computed tomography shows bilateral ureteral dilation, a normal bladder volume, and the bladder wall.

To determine the cause of the patient’s hydronephrosis and ureteral dilatation, we performed an endoscopic examination, which included the renal pelvis, ureter, and bladder. Multiple granulomatous masses were found in the bladder, and the bladder neck was considerably elevated (Figure 2). Taking into consideration the urodynamic results and subjective symptoms of the patient, we finally diagnosed her with BOO.

Figure 2.

An endoscopic examination shows multiple nodular masses in the trigone and in both side walls of the bladder.

Therefore, we considered transurethral resection of the tumor, and a small amount of bladder neck tissue at the 6 o’clock position was appropriate. The operation proceeded smoothly, and the patient was discharged after 3 days with no complications. Histopathological results led to the diagnosis of XC (Figures 3, 4). Immunohistochemistry showed CD68 (+), cytokeratin (+), Ki67 (1%+), and vimentin (+). The patient received levofloxacin capsules for half a month. Follow-up cystourethroscopy, which was performed 3 months after the operation, showed a normal bladder mucosa. CT showed that bilateral ureteral dilation was reduced. A re-examination of urodynamics showed that the maximum urine flow rate was 25 mL/s, there was no residual urine, and the detrusor pressure at the maximum urine flow rate was <20 cmH₂O. The reporting of this study conforms to the CARE guidelines. ³

Figure 3.

Histology shows infiltration of lymphocytes, plasma cells, mononuclear macrophages, and large sheet foam cells in the lamina propria (hematoxylin and eosin, ×200).

Figure 4.

Immunohistochemistry shows a CD68-positive epithelioid and foamy macrophages (hematoxylin and eosin, ×100).

Discussion

Xanthogranulomatous is a rare, benign, chronic inflammation. This condition occurs in the bladder and is relatively rare. The etiology and pathogenesis of XC may include urachal remnant irritation, urothelial metaplasia caused by chronic bacterial infection, immune disorders, abnormal lipid metabolism, and local allergies caused by tumors. ^{1 , 2} Men and women can develop XC. XC is more common in women aged between 30 and 50 years old, and only 30 adult cases and 3 pediatric cases have been reported in the English literature. ⁴

The clinical symptoms of XC are similar to other types of cystitis, including bladder irritation, dysuria, lower abdominal pain, and discomfort. ⁵ Most patients with XC have remarkable imaging findings in the bladder, but our patient did not. We had to perform endoscopy to determine whether our patient’s bladder and urethra were abnormal. Finally, the patient was diagnosed with BOO. There is no uniform international standard for diagnosing female BOO. The pathophysiology of BOO in women might be similar to that in men, but further evaluation is necessary to define the mechanism. Urodynamic data can also provide diagnostic evidence for BOO. The criterion of the maximum urinary flow rate to define female BOO ranges from 1115 mL/s, and the detrusor pressure at the maximum urine flow rate ranges from 21 to 25 cmH₂O. ⁶

XC needs to be distinguished from bladder cancer. Bladder cancer is more likely to occur in the triangle area of the bladder, and usually has painless gross hematuria. The diagnosis of XC can be confirmed by combining imaging, urine exfoliation cytology, and a cystoscopic biopsy. Additionally, XC needs to be distinguished between glandular cystitis and interstitial cystitis. The inflammatory changes caused by glandular cystitis are usually limited to the mucosal layer and submucosal layer, and do not involve the muscle layer. The main feature of interstitial cystitis is that a bladder filling experiment shows submucosal spots, flaky hemorrhage, or Hunner’s ulcer.

The diagnosis of XC depends on a histopathological examination. The parenchyma of the pathological tissue shows tumor-like lesions with lipid-containing macrophages, multinucleated giant cells, lymphocytes, plasma cells infiltrated by fibroblast proliferation, and angiogenesis. Furthermore, foam macrophages are strongly positive for prostate-specific antigen staining.^7,8 A large number of foam cells under light microscopy is the basic characteristic for diagnosing XC. Ki67 staining of 1% indicates that the lesions are benign.

In our case, the patient had repeated urinary tract infections due to BOO and long-term bacterial infection triggered by XC. Therefore, transurethral resection of the bladder neck and granulomatous lesions was necessary. The surgical method of XC can be determined according to the degree of invasion, the location of the lesion, and the patient’s wishes. In any case, the lesion should be resected as much as possible because most of the lesion contains pathogenic bacteria. ⁹ In our patient, the follow-up results were satisfactory. Whether BOO caused by benign prostatic hyperplasia in men also increases the incidence of XC is unknown. Further research on this possibility is required.

In conclusion, if imaging examinations show obvious bladder space-occupying lesions, the diagnosis and treatment of XC are relatively simple. To some extent, prevention is more effective than a therapeutic strategy.