Clinicopathological Features of Nephrogenic Adenomas Mimicking Malignancy

Abstract

Nephrogenic adenoma (NA) is a rare benign lesion of the urinary tract with diverse clinical and histopathological features that may mimic malignancy. This study aimed to evaluate the clinicopathological features, histological patterns, and associated conditions in a single-center cohort, and to emphasize the differential diagnosis from other malignant entities that may pose diagnostic challenges. A retrospective analysis was performed on 49 biopsy specimens from 39 patients diagnosed with NA. Clinical data, cystoscopic findings were recorded. The median patient age was 68 years, with a male predominance (76.9%). The most common presenting symptoms were hematuria and dysuria (28.2% each). The bladder was the most frequent site of involvement (79.5%). Histologically, flat (67.3%) and tubular (59.2%) patterns were predominant, and most cases exhibited multiple coexisting patterns. Accompanying neoplasia was identified in 71.8% of the cases, most commonly invasive urothelial carcinoma (53.8%). Recurrence occurred in a subset of patients. NA demonstrates marked histologic heterogeneity and is frequently coexists with urothelial neoplasia. Awareness of its diverse morphology and frequent coexistence with malignancy is essential to avoid diagnostic pitfalls and ensure appropriate clinical management.