Nephrogenic adenoma of the urinary bladder

Acute post-renal kidney graft dysfunction due to cytomegalovirus-positive nephrogenic adenoma-case report and review of the literature

Tissue-invasive cytomegalovirus (CMV) disease represents a well-recognized complication after kidney transplantation. However, direct involvement of the urogenital tract and CMV-ureteritis occur less frequently. Nephrogenic adenomas are benign lesions of the urinary tract preferentially reported in kidney transplant recipients. We herein report a second case of a 33-year-old male kidney transplant recipient with acute post-renal allograft dysfunction due to CMV-positive ureteral nephrogenic adenoma. A causal connection might be suspected but remains to be proven.

Bladder nephrogenic adenoma as a complication of surgical correction of megaureter

Background

Bladder nephrogenic adenoma (BNA) is a rare benign proliferative pathology of its mucosa. The etiopathogenesis of the disease remains uncertain, and the treatment is still challenging.

Case presentation

In this article, we present a clinical case of bladder nephrogenic adenoma in a 6-year-old boy. Clinical symptoms of the disease appeared 3 years after surgical treatment of obstructive megaureter. Histopathological and immunohistochemical examination of glandular polyp biopsies allowed excluding the tumor process and making a diagnosis.

Conclusion

Nephrogenic adenomas demonstrate a variety of morphologic patterns that may occasionally be confused with malignant processes. We described the endoscopic characteristics of BNA and characterized its histological and immunohistochemical features in a boy after ureteroneocystostomy.

Nephrogenic metaplasia in a female person with spinal cord injury: chronic irritation caused by Foley balloon was aggravated by a large uterine fibroid pressing upon the bladder wall for several years: a case report

INTRODUCTION

Chronic irritation caused by urinary catheter may predispose to metaplastic changes in the bladder and very rarely, nephrogenic metaplasia.

CASE PRESENTATION

A 53-year-old lady with T-2 paraplegia and urethral catheter drainage for 27 years presented with haematuria. MRI of pelvis, performed seven years ago, showed a 10 cm intramural fibroid within the anterior aspect of the uterine body which was pushing the collapsed urinary bladder containing the Foley catheter to the left. The patient decided to avoid surgery to remove the fibroid at that time. Ultrasound scan of the urinary bladder done now, revealed a polypoidal lesion in the left superolateral wall. Superficial enhancing lesion with no invasion of the bladder wall was seen in the CT urography. Cystoscopy showed extensive catheter reaction, and in the centre, a slightly more papillary area, which was resected. Histology revealed inflamed bladder mucosa showing tubular and papillary structures lined by cuboidal epithelial cells; the features were of nephrogenic metaplasia. The tubular and papillary structures were lined by cells showing positive immunohistochemical staining for CK7 and PAX8.

DISCUSSION

Catheter reaction and nephrogenic metaplasia was found in the left superolateral wall of the bladder where the large uterine fibroid was pushing the balloon of the catheter against the bladder wall for more than seven years. The patient decided to undergo surgery to remove the large fibroid and thereby prevent further pressure effects upon the urinary bladder.

Recurrence of childhood nephrogenic adenoma in urinary bladder developed four years after previous surgery despite intravesical sodium hyaluronate therapy

Nephrogenic adenoma (NA) is a rarely seen benign metaplastic lesion of the urinary tract. Its etiology is uncertain, but induced by chronic inflammation, irritation, and trauma. NA is located in the urinary tract, most commonly in the bladder. NA usually presents with hematuria and lower urinary tract symptoms. In the literature it is mostly seen in adults but about 30 cases of NA's have been reported in children. Treatment of intravesical lesions consists of transurethral resection (TUR) and fulguration and rarely partial or total cystectomy may be required in ineffective TUR. Recurrence rate is high during long-term follow-up. The intravesical application of sodium hyaluronate produces a protective effect on the glycosaminoglycan layer and delays or prevents its recurrence. We report a case of recurrent NA of the bladder in a pediatric male patient who was presented four years after previous surgery despite intravesical sodium hyaluronate therapy.

Fibromyxoid nephrogenic adenoma protruding in a renal cortical cyst. A rare morphological variant in an outstanding location

Nephrogenic adenoma (NA) is an unusual, benign lesion of the urinary tract, generally presenting in the bladder and with less frequency in the renal pelvis, urethra or ureter. It consists of tubules, microcysts and papillae lined by a single layer of low cuboidal epithelium without atypia. Recently, a fibromyxoid variant mimicking an infiltrating mucinous adenocarcinoma has been described. We report hereby the case of a 70-year-old female with a fibromixoid NA protruding in a renal cortical cyst. Only one case of NA in a renal cortical cyst has been found in the literature and it was of the classical type. The development of a NA in a renal cortical cyst lends support to the theory that the NA results from proliferation of secondarily implanted exfoliated renal epithelial cells.

Do We Need Surveillance Urethro-Cystoscopy in Patients with Neurogenic Lower Urinary Tract Dysfunction?

PURPOSE

To examine the value of surveillance urethro-cystoscopy in patients with neurogenic lower urinary tract dysfunction (NLUTD) in regard to the conflicting literature as it is generally agreed that patients with NLUTD are at increased risk for bladder cancer.

MATERIALS AND METHODS

In a cross-sectional study, a consecutive series of 129 patients (50 females, 79 males, mean age 51, range 18-88) suffering from NLUTD for at least 5 years was prospectively investigated using urethro-cystoscopy and bladder washing cytology at a single university spinal cord injury (SCI) center.

RESULTS

Due to suspicious urethro-cystoscopy and/or bladder washing cytology findings, 13 (10%) of 129 patients underwent transurethral resection of the bladder lesion and/or random bladder biopsies. Overall, 9 relevant histological findings were found in 5% (7/129) of our patients: bladder melanosis (n = 1), nephrogenic adenoma (n = 3), keratinizing squamous metaplasia (n = 1), intestinal metaplasia (n = 3), and muscle-invasive adenocarcinoma of the bladder (n = 1).

CONCLUSIONS

Using surveillance urethro-cystoscopy, we found relevant histological findings in 5% of our patients suffering from NLUTD for at least 5 years. Thus, surveillance urethro-cystoscopy might be warranted, although the ideal starting point and frequency remain to be determined in further prospective studies.

Nephrogenic Adenoma of the Urinary Bladder: A Review of the Literature

Background. Nephrogenic adenoma of the urinary bladder (NAUB) is a rare lesion associated with nonspecific symptoms and could inadvertently be misdiagnosed. Aim. To review the literature. Methods. Various internet search engines were used. Results. NAUB is a benign tubular and papillary lesion of the bladder, is more common in men and adults, and has been associated with chronic inflammation/irritation, previous bladder surgery, diverticula, renal transplantation, and intravesical BCG; recurrences and malignant transformations have been reported. Differential diagnoses include clear cell adenocarcinoma, endocervicosis, papillary urothelial carcinoma, prostatic adenocarcinoma of bladder, and nested variant of urothelial carcinoma; most NAUBs have both surface papillary and submucosal tubular components; both the papillae and tubules tend to be lined by a single layer of mitotically inactive bland cells which have pale to clear cytoplasm. Diagnosis may be established by using immunohistochemistry (positive staining with racemase; PAX2; keratins stain positive with fibromyxoid variant), electron microscopy, DNA analysis, and cytological studies. Treatment. Endoscopic resection is the treatment but recurrences including sporadic malignant transformation have been reported. Conclusions. There is no consensus on best treatment. A multicentre study is required to identify the treatment that would reduce the recurrence rate, taking into consideration that intravesical BCG is associated with NAUB.

Nephrogenic adenoma of the ureter

Nephrogenic adenoma (NA) is an uncommon benign lesion of the urothelial tract. The diagnostic features that are useful in the recognition of this benign entity are: the characteristic mixture of various architectural patterns, associated stromal edema and inflammation, hyaline sheath around tubules, and lack of mitotic activity. Although NA appears with hematuria or obstruction, frequently found incidentally in endoscopy or imaging modalities.

Recurrent nephrogenic adenoma in bladder diverticulum: Case report and literature review

Nephrogenic adenoma is an uncommon benign lesion of the urinary tract induced by chronic irritation of the vesical mucosa, due to infection, trauma, surgery, calculi, foreign bodies and chemical agents. A 68-year-old male was admitted to our linic for a periodical cystoscopic evaluation as part of a follow-up initiated due to a past transitional cell carcinoma. The scheduled cystoscopy revealed, within a bladder diverticulum, an unexpected and completely asymptomatic nephrogenic adenoma that we removed by transurethral resection. We followed up the patient at 24 months, then later we made the diagnosis of nephrogenic adenoma. During this time, the patient experienced three relapses within the same diverticulum, always involving a nephrogenic adenoma we persistently treated by transurethral resections. As the nephrogenic adenoma is considered a benign lesion without any direct evidence of a possible evolution to an overt cancer, we successful attempted a half-yearly cystoscopic follow-up to control the growth of a highly recurrent benign entity, interposing between controls a periodical imaging. This paper represents the second report of a nephrogenic adenoma within a bladder diverticulum, but the first case of a nephrogenic adenoma highly recurrent within the same diverticulum and managed conservatively by regular transurethral resection scheduled over the time.

Nephrogenic Adenoma of the Urinary Tract

Nephrogenic adenoma (NA) is an uncommon and intriguing lesion in the urinary tract. The pathogenesis of NA is not entirely clear. NA was considered to be a metaplastic process of the urothelium in response to chronic irritation of the urinary tract. However, recent evidence has shown that NA is not a metaplastic lesion but rather a proliferation of exfoliated and implanted renal epithelial cells in the urinary tract. Histologically, NAs exhibit, singly or in combination, tubules, small papillae, and microcystic structures lined by cells with little cytological atypia and focal hobnail changes. Solid formations and compressed spindled cells within a fibromyxoid background are rarely observed. Differential diagnosis includes, but is not limited to, malignant neoplasms occurring at the same sites, in particular urothelial carcinoma with deceptively bland morphology (with small tubules, microcystic and nested variants), prostatic adenocarcinoma, and clear cell adenocarcinoma. Immunohistochemical studies with antibodies targeting members of the paired box gene family (PAX2 and/or PAX8) in NAs may be helpful in the differential diagnosis of urothelial lesions and prostatic adenocarcinoma. NAs are most likely to be confused with clear cell adenocarcinoma, especially in small biopsy specimens. This is confounded by both lesions being frequently positive for PAX2, PAX8, and CK7 and not infrequently positive for p504S (α-methylacyl-CoA-racemase, AMACR) by immunohistochemistry. Recognition of its characteristic morphological patterns and awareness of its unusual architectural and cytological features are important in making the diagnosis of NA and distinguishing this lesion from its mimickers.

Nephrogenic adenoma of the bladder in a prune belly syndrome patient: case report and review of the literature

Nephrogenic adenoma (NA) is a rare lesion of the urinary tract widely considered to be a metaplastic response to urothelial injury. Herein, we present the case of an 8-year-old male with prune belly syndrome who presented with gross hematuria. Investigation revealed a bladder mass; however, upon cystoscopic examination, multiple polypoid lesions were identified. Microscopic examination revealed NA of the bladder. To our knowledge, this is the second reported case of NA of the bladder in association with prune belly syndrome.