Nephrogenic Adenoma After Urethral Reconstruction Using Bladder Mucosa: Report of 6 Cases and Review of the Literature

Eosinophilic cystitis and nephrogenic adenoma of the bladder: a rare association of 2 unusual findings in childhood

Neither eosinophilic cystitis nor nephrogenic adenoma is often diagnosed in children, with few pediatric cases being reported in the literature. Although these maladies share the same predisposing conditions, namely, chronic irritation or injury to the urothelium and lower urinary tract and symptoms such as dysuria, hematuria, and urinary frequency, their concomitance is exceptional. Herein, we report the case of an 8-year-old boy with a previous history of bladder surgery presenting histologically diagnosed eosinophilic cystitis and nephrogenic adenoma.

Clear cell adenocarcinoma of urinary bladder and urethra: another urinary tract lesion immunoreactive for P504S

CONTEXT

Clear cell carcinoma of the urinary bladder/ urethra is a rare tumor histologically resembling the neoplasms in the female genital tract. Adequate characterization of this tumor has been hampered by its rarity. alpha-Methylacyl-CoA racemase (AMACR)/P504S has been reported to be positive in prostatic adenocarcinoma, papillary renal cell carcinoma, and gastrointestinal neoplasmas; however, it has never been studied in clear cell carcinoma of the lower urinary tract.

OBJECTIVE

To investigate the immunohistochemical staining profile in 4 primary clear cell carcinomas of the urinary tract, including P504S, which has not been previously evaluated in these tumors.

DESIGN

Four cases of clear cell adenocarcinoma were retrieved from our archives: 2 cases from the urinary bladder (one each from a man and a woman) and 2 cases from the urethra (both from women, 1 in a diverticulum). Immunohistochemistry performed on the cases were P504S, K903, cytokeratin (CK) 7, CK20, CA 125, and p63.

RESULTS

We found that clear cell carcinomas had a distinct immunoreactive profile: strongly positive for P504S, K903, and CK7, and negative for p63. Two cases were also positive for CA 125 and CK20.

CONCLUSION

The immunohistochemical profile of clear cell carcinomas shares some similarity to conventional urothelial carcinoma; however, it deviates from those tumors in being positive for P504S and negative for p63. This staining profile may suggest a nonurothelial origin for these tumors, may serve as a useful tool in the differential diagnosis of this tumor, and may reflect its etiology. Because similar expression of P504S is also seen in nephrogenic adenomas, this marker should not be used to differentiate nephrogenic adenomas from clear cell adenocarcinomas.

Derivation of nephrogenic adenomas from renal tubular cells in kidney-transplant recipients

BACKGROUND

Nephrogenic adenomas are benign, tumor-like lesions within the urothelial mucosa of the urinary tract that are not uncommon in renal-transplant recipients. We investigated the origin of nephrogenic adenomas in renal-transplant recipients.

METHODS

Tissue sections were analyzed by fluorescence in situ hybridization with the use of probes for the X and Y chromosomes, by immunohistochemical methods with the use of antibodies to renal tubular antigens, and by lectin histochemical methods. Forty-six nephrogenic adenomas from 29 patients were analyzed.

RESULTS

All nephrogenic adenomas in 14 female recipients of transplants from male donors and 10 male recipients of transplants from female donors showed the same sex-chromosome status as the donor kidney, but not the same sex-chromosome status as the recipient's surrounding bladder tissue. The nephrogenic adenomas from all 6 female recipients of transplants from female donors showed female chromosomes, and those from the 16 male recipients of transplants from male donors showed male chromosomes. The presence of aquaporin 1, PAX2, and lectin-binding capacity for peanut agglutinin, Lotus tetragonolobus agglutinin, and Sophora japonica agglutinin in nephrogenic adenomas indicated an origin from renal tubular cells.

CONCLUSIONS

Nephrogenic adenomas in renal-transplant recipients are derived from tubular cells of the renal transplants and are not metaplastic proliferations of the recipient's bladder urothelium.

[Urethral nephrogenic adenoma in a young male. Report of a case]

Nephrogenic adenoma is a rare urothelial neoformation. It is well known the association to infective diseases and stones; the most common localization is in the bladder. We report the case of a young male without previous disease who showed a nephrogenic adenoma in the urethra, it was managed with transurethral resection and surveillance.

Use of bladder mucosal graft for urethral reconstruction

BACKGROUND

The ideal tissue for complex urethral reconstruction has yet to be determined, especially in patients with deficient preputium. The use of bladder mucosa as a free graft could be an alternative in these problem cases.

METHODS

Bladder mucosa graft urethroplasty was performed on 14 patients with penoscrotal or scrotal hypospadias. The mean age of the patients was 18.7 (range 14-23) years. Ten cases were subjected to primary urethral reconstruction while four cases had previous hypospadias repair.

RESULTS

Complete urethral replacement by the bladder mucosa tube was performed in six patients. Meatal problems occurred in two (33.33%) patients and proximal fistula formed in one (16.67%) patient. A bladder mucosa graft was combined with preputial or tunica vaginalis grafts distally in eight cases, and one patient in the tunica vaginalis group developed fistula at the anastomosis of the bladder mucosa and tunica vaginalis grafts. The overall complication rate was 28.6%.

CONCLUSIONS

Our initial results showed that bladder mucosa grafts can be used successfully for urethral reconstruction especially when combined with preputial or tunica vaginalis grafts distally.

Atypical nephrogenic metaplasia of the urinary tract: a precursor lesion?

BACKGROUND

Nephrogenic metaplasia with cytologic atypia (atypical nephrogenic metaplasia) is occasionally encountered and its biologic potential is uncertain.

METHODS

The authors describe 18 cases of atypical nephrogenic metaplasia characterized by the presence of prominent cytologic atypia, including nuclear enlargement, nuclear hyperchromasia, and enlarged nucleoli. DNA ploidy analysis by digital image analysis and immunostaining for high-molecular-weight cytokeratin (34betaE12), cytokeratin 7, cytokeratin 20, carcinoembryonic antigen (CEA), epithelial membrane antigen (EMA), p53, and MIB-1 were performed in 9 cases.

RESULTS

The mean patient age was 62 years (median, 65 years; range, 39-84 years). The male-to-female ratio was 2.6:1. Two patients had a history of noninvasive papillary urothelial carcinoma. The typical clinical presentation was hematuria (8 patients) and voiding symptoms (5 patients). Cystoscopic findings were suspicious for neoplasm in 7 of 13 cases. The neoplastic cells were positive for high-molecular-weight cytokeratin, cytokeratin 7, and EMA, and were usually negative for cytokeratin 20 and CEA. p53 nuclear accumulation and increased MIB-1 labeling index were seen in 4 cases. DNA ploidy analysis showed aneuploid pattern in 2 of 9 cases. The mean patient follow-up was 3.5 years (range, 0.5-10.6 years); 2 patients had recurrent nephrogenic metaplasia, and the remainder were alive without recurrence or urothelial carcinoma.

CONCLUSIONS

Atypical nephrogenic metaplasia is benign; it occasionally displays substantial cytologic abnormalities of no apparent clinical significance. Awareness of the spectrum of cytologic changes within this entity is critical to prevent overdiagnosis of cancer and avoid unnecessary treatment. There is no direct evidence that links atypical nephrogenic metaplasia to cancer.

Hypospadias

The incidence of hypospadias is increasing. Decreased androgen sensitivity, 5alpha-reductase deficiency and chromosomal abnormalities are causes of the disease. Nonirritant suture material, coverage of the urethral reconstruction by additional tissue and perioperative care positively influence the outcome. Complication rates after repair of distal hypospadias are low. For severe hypospadias staged procedures provide good results. Buccal mucosa is promising for initial repair and repeat cases. Psychosocial function in patients with severe hypospadias is normal.