Nephrogenic Adenomas in Pediatric Patients: A Morphologic and Immunohistochemical Study of 21 Cases

Abstract

Similar to nephrogenic adenomas in adults, those in children are rare benign lesions that often occur in the setting of previous surgery or chronic irritation of the urinary tract. These lesions often present with hematuria and/or as polypoid or papillary lesions on cystoscopy, which may indicate malignancy. We sought to evaluate the various patterns of nephrogenic adenoma occurring in the pediatric population and better characterize the immunophenotype of these lesions. We reviewed 21 cases of nephrogenic adenomas from urinary bladder biopsies of 16 patients. Most patients had a history of urinary bladder augmentation with recurrent urinary stones and urinary tract infections. Many cases presented as a papillary or polypoid mass on cystoscopy. The most common morphologic patterns are papillary, tubulocystic, and a mixed pattern of papillary and tubulocystic, followed by cystic and tubular. On immunostaining, PAX-2, PAX-8, CK7, and MUC-1 provided the most diffuse and intense positive reactivity for nephrogenic adenoma, whereas CD10 and P504S were focal and lesser in intensity when positive. p63 and PAX-5 were consistently negative. We conclude that, although rare in children, nephrogenic adenoma should be included in the differential diagnosis of papillary/polypoid lesions in the urinary tract, especially in the context of previous surgery, chronic irritation from recurrent urinary tract infections, or stones. The immunohistochemistry profile of nephrogenic adenomas in our study also provides evidence that these are derived from distal renal tubular cells. In difficult cases, an immunohistochemical panel consisting of cytokeratin 7, PAX-2, PAX-8, and MUC-1 may be useful.

Nephrogenic adenoma in elderly patients: Three case reports

“…However, the studies of Husain et al and Kao et al involved pediatric cases of NA (8,9). Several predisposing factors have been reported to be associated with NA, in adults as well as in children (1,8,9,11,12).…”

“…However, the studies of Husain et al and Kao et al involved pediatric cases of NA (8,9). Several predisposing factors have been reported to be associated with NA, in adults as well as in children (1,8,9,11,12). Our patients had also undergone various treatments prior to the development of the NAs; 1 patient was subjected to TUL due to a ureteral stone and TUR-P due to BPH; 1 patient had received TUR due to urothelial carcinoma in the urinary bladder; and the third patient had received TUR due to urothelial carcinoma in the urinary bladder, followed by treatment with BCG.…”

“…Furthermore, Husain et al reported 18 cases of NA in pediatric patients, ranging in age from 2 to 19 years (8), whereas Kao et al reported 21 cases of pediatric NAs, with an age range of 2-16 years (9). The usual clinical presentation is hematuria, dysuria and frequency of micturition (10).…”

“…The usual clinical presentation is hematuria, dysuria and frequency of micturition (10). Several predisposing factors have been reported to be associated with NA, in adults as well as in children, including genitourinary trauma, chronic inflammation, prior surgery, renal calculi, repeated instrumentation, irritated anatomical anomalies and pelvic irradiation, bacillus Calmette-Guérin (BCG) immunotherapy and diverticuli (1,8,9,11,12).…”

Nephrogenic Adenoma of the Urinary Tract in Pediatric Patients: A Report of 2 Cases

“…Papillary projections may also be seen. The small tubules are often surrounded by a thickened hyalinised basement membrane without a desmoplastic stromal response (2,3,7). The main differential diagnoses include prostatic adenocarcinoma and clear cell adenocarcinoma of the urethra in adults and rhabdomyosarcoma and transitional cell carcinoma in children (1,4,7).…”