The nephrogenic adenoma of the bladder: 8 cases and literature review

Objective To analyze the clinical characteristics of nephrogenic adenoma of the bladder. Methods The clinical and pathological data of 8 patients with bladder nephrogenic adenoma, during the period from July 2016 to June 2019, were retrospectively analyzed. Patients’ age were 33 to 71 years old and the average age was 55, including 5 males and 3 females. The clinical manifestations were hematuria in 7 cases, urinary tract irritation in 6 cases, and no obvious symptoms in 1 case. There were 7 cases with cystitis, 3 cases with urolithiasis, 2 cases with bladder cancer, 1 case with invasive colonic mesentery fibroma, and 1 case without other complications. 5 cases had the history of urological operation. The predilection site was the lateral wall with 5cases; 5 cases were solitary; the average maximum diameter of the tumor was 0.9 cm (range 0.1-1.8 cm). Under cystoscope, papillary mass can be seen, the surface is bright red, the pedicle is not obvious, the papilla is thick and short, easy to bleed when touching; some of them are scattered and lichen like changes. All patients received transurethral resection of bladder mucosa. Results Pathological examination shows that the bladder mucosa showed chronic inflammation, interstitial edema, granulation tissue hyperplasia, eosinophil infiltration and metaplasia of mesonephroid epithelium. All of the 8 patients were followed up by telephone for 2 to 38 months, with an average of 17.1 months. So far, neither recurrence has been detected. Conclusions The diagnosis of nephrogenic adenoma of the bladder depends on pathological examination. It must be totally removed during operation. The recurrence and malignancy should be treated in time after operation. Key words: Urinary bladder neoplasms; Nephrogenic adenoma; Pathology