Nephrogenic adenoma of the urinary bladder: A Histopathological case report

We report the case of a 31-year-old man presenting with painless macroscopic hematuria, a rare symptom in young adults that often requires a thorough evaluation to exclude an underlying malignancy. Initial uroimaging and cystoscopic examination revealed a papillary lesion originating from the bladder neck and extending to the prostatic urethra, strongly suggesting a neoplastic process. The patient underwent transurethral resection of the bladder tumor (TURBT), and histopathological analysis of the resected tissue revealed architectural and cytological features characteristic of a nephrogenic adenoma, a rare benign metaplastic lesion of the urothelium. Microscopic examination revealed tubular and papillary structures lined with cuboidal to nail-shaped epithelial cells, embedded in an edematous stroma. No cytological atypia, mitotic activity, or signs of urothelial carcinoma or other malignant transformation were identified. Nephrogenic adenoma is often misdiagnosed as carcinoma due to its histological resemblance to malignant entities, including adenocarcinoma and nested variants of urothelial carcinoma. This case highlights the critical importance of accurate histopathological interpretation to avoid overtreatment, particularly in young patients, for whom the psychosocial and physical consequences of a cancer diagnosis can be profound. This report aims to raise awareness among clinicians about this rare entity, highlight the diagnostic challenges it poses, and emphasize the need for clinicopathological correlation to ensure appropriate patient management. The patient's postoperative course was uneventful, and no recurrence was observed during short-term follow-up.