Nephrogenic adenoma in elderly patients: Three case reports

Area of Science:

• Uropathology
• Oncology
• Histopathology

Background:

• Nephrogenic adenoma (NA), also known as nephrogenic metaplasia, is an uncommon benign lesion of the urinary tract.
• NA presents with characteristic histological features, including tubular and papillary formations lined by cuboidal to columnar epithelium.
• Immunohistochemical markers such as PAX2, PAX8, and cytokeratin 7 positivity, with negativity for p63 and prostate-specific antigen, aid in diagnosis.

Purpose of the Study:

• To present three cases of nephrogenic adenoma in elderly male patients.
• To describe the predisposing factors associated with NA development in these cases.
• To emphasize the histological and immunohistological characteristics of NA and its differentiation from other urinary tract tumors.

Main Methods:

• Case study of three elderly male patients diagnosed with nephrogenic adenoma.
• Histopathological examination of urinary bladder lesions.
• Immunohistochemical analysis using specific markers (PAX2, PAX8, cytokeratin 7, p63, prostate-specific antigen).

Main Results:

• Three cases of NA were identified in elderly males with predisposing factors including transurethral lithotripsy, transurethral resection of urothelial carcinoma, and Bacillus-Calmette-Guérin treatment.
• Histological and immunohistological findings were consistent with previously reported NA cases.
• One patient presented with a pseudoinvasive pattern, underscoring the need for careful evaluation.

Conclusions:

• Nephrogenic adenoma is a benign, tumor-like lesion requiring accurate morphological and immunohistological differentiation.
• Predisposing factors may play a role in NA development.
• Distinguishing NA from urothelial carcinoma and prostate cancer invasion is crucial for appropriate patient management.