Pathology Page
Nephrogenic Adenoma of the Pediatric Ureter A 12-year-old male with a history of cystinuria complicated by nephrolithiasis was seen in the pediatric nephrology clinic for routine followup. Renal bladder ultrasound demonstrated moderate to severe hydronephrosis and proximal hydroureter on the right side. Urothelial thickening and echogenic debris were noted in the lumen throughout a fairly long segment of ureter. On ureteroscopy the entire ureteral lumen contained numerous polyps, which appeared edematous and obstructive (fig. 1). The polyps extended from the ureterovesical junction to the ureteropelvic junction. Pathological examination of tissue obtained by ureteroscopic biopsy demonstrated broad papillary fronds with paucicellular stroma lined by a single layer of cuboidal epithelial cells with eosinophilic cytoplasm and uniform round nuclei. Scattered mixed inflammatory cells were present in the stroma. No mitotic figure or significant cytological
Figure 1. Ureteroscopy shows gross architecture of multiple ureteral nephrogenic adenomas.
0022-5347/15/1934-1377/0 THE JOURNAL OF UROLOGY® © 2015 by AMERICAN UROLOGICAL ASSOCIATION EDUCATION
AND
RESEARCH, INC.
atypia was seen (fig. 2). These findings were most consistent with nephrogenic adenoma (NA). Given the history of cystinuria, observation was considered less than ideal. The patient was subsequently returned to the operating room. A 5Fr angiographic catheter was advanced over a guide wire under fluoroscopic guidance. A mixture of 20 mg sodium hyaluronate in 30 ml normal saline was instilled in 5 ml increments along the course of the ureter. NA is a rare tumor initially described as hamartoma in 1949 by Davis1 and better described as resembling renal tubules in 1950 by Friedman and Kuhlenbeck.2 It is thought to be related to chronic irritation of the urothelium. Inciting factors are believed to include trauma, infection, surgery, renal transplantation, stones and instrumentation. Our patient had undergone 8 previous procedures for stone disease in the affected ureter. Bladder NA is thought to be more common in men than in women (2:1) and in children bladder
Figure 2. Histological section of biopsy of ureteral lesions reveals broad papillary fronds with paucicellular stroma lined by layer of cuboidal epithelial cells with eosinophilic cytoplasm and uniform round nuclei. Reduced from x100.
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PATHOLOGY PAGE
NA is thought to significantly predominate in boys (5:1).3 Histologically NA may show tubular, cystic, papillary and solid growth patterns. However, the most common form is a tubular structure surrounded by a thick hyalinized basal membrane, which may include clear or cubic cells with eosinophilic cytoplasm or hobnail cells.4 Our patient had these findings without mitotic figures or significant cytological atypia, which ruled out malignancy. Campobasso et al described the use of sodium hyaluronate to treat diffuse NA of the bladder.5 In that study the same concentration was used and instilled twice each week for 2 weeks. The treatment was then instilled once every 2 weeks for 5 months. Improvement in hematuria, stranguria, calculi and bladder capacity was subsequently recorded. Symptomatic ureteral NA remains a rare finding. To our knowledge we report the first pediatric case of ureteral NA in the English literature. Our limited experience suggests that sodium hyaluronate
instillation is a viable option in patients with symptomatic obstruction. Adam J. Rensing, Joel F. Koenig and Gino J. Vricella Division of Urologic Surgery and
Jennifer K. Sehn Department of Pathology and Immunology Washington University School of Medicine St. Louis, Missouri 1. Davis TA: Hamartoma of the urinary bladder. Northwest Med 1949; 48: 182. 2. Friedman NB and Kuhlenbeck H: Adenomatoid tumors of the bladder reproducing renal structures (nephrogenic adenomas). J Urol 1950; 64: 657. 3. Heidenreich A, Zirbes TK, Wolter S et al: Nephrogenic adenoma: a rare bladder tumor in children. Eur Urol 1999; 36: 348. 4. Doluoglu OG, Acarer EY, Yavuz A et al: Nephrogenic adenoma of the ureter. Rare Tumors 2012; 4: e28. 5. Campobasso P, Fasoli L and Dante S: Sodium hyaluronate in treatment of diffuse nephrogenic adenoma of the bladder in a child. J Pediatr Urol 2007; 3: 156.
Nephrogenic Adenoma of the Pediatric Ureter A 12-year-old male with a history of cystinuria complicated by nephrolithiasis was seen in the pediatric nephrology clinic for routine followup. Renal bladder ultrasound demonstrated moderate to severe hydronephrosis and proximal hydroureter on the right side. Urothelial thickening and echogenic debris were noted in the lumen throughout a fairly long segment of ureter. On ureteroscopy the entire ureteral lumen contained numerous polyps, which appeared edematous and obstructive (fig. 1). The polyps extended from the ureterovesical junction to the ureteropelvic junction. Pathological examination of tissue obtained by ureteroscopic biopsy demonstrated broad papillary fronds with paucicellular stroma lined by a single layer of cuboidal epithelial cells with eosinophilic cytoplasm and uniform round nuclei. Scattered mixed inflammatory cells were present in the stroma. No mitotic figure or significant cytological
Figure 1. Ureteroscopy shows gross architecture of multiple ureteral nephrogenic adenomas.
0022-5347/15/1934-1377/0 THE JOURNAL OF UROLOGY® © 2015 by AMERICAN UROLOGICAL ASSOCIATION EDUCATION
AND
RESEARCH, INC.
atypia was seen (fig. 2). These findings were most consistent with nephrogenic adenoma (NA). Given the history of cystinuria, observation was considered less than ideal. The patient was subsequently returned to the operating room. A 5Fr angiographic catheter was advanced over a guide wire under fluoroscopic guidance. A mixture of 20 mg sodium hyaluronate in 30 ml normal saline was instilled in 5 ml increments along the course of the ureter. NA is a rare tumor initially described as hamartoma in 1949 by Davis1 and better described as resembling renal tubules in 1950 by Friedman and Kuhlenbeck.2 It is thought to be related to chronic irritation of the urothelium. Inciting factors are believed to include trauma, infection, surgery, renal transplantation, stones and instrumentation. Our patient had undergone 8 previous procedures for stone disease in the affected ureter. Bladder NA is thought to be more common in men than in women (2:1) and in children bladder
Figure 2. Histological section of biopsy of ureteral lesions reveals broad papillary fronds with paucicellular stroma lined by layer of cuboidal epithelial cells with eosinophilic cytoplasm and uniform round nuclei. Reduced from x100.
http://dx.doi.org/10.1016/j.juro.2015.01.067 Vol. 193, 1377-1378, April 2015 Printed in U.S.A.
www.jurology.com
j
1377
1378
PATHOLOGY PAGE
NA is thought to significantly predominate in boys (5:1).3 Histologically NA may show tubular, cystic, papillary and solid growth patterns. However, the most common form is a tubular structure surrounded by a thick hyalinized basal membrane, which may include clear or cubic cells with eosinophilic cytoplasm or hobnail cells.4 Our patient had these findings without mitotic figures or significant cytological atypia, which ruled out malignancy. Campobasso et al described the use of sodium hyaluronate to treat diffuse NA of the bladder.5 In that study the same concentration was used and instilled twice each week for 2 weeks. The treatment was then instilled once every 2 weeks for 5 months. Improvement in hematuria, stranguria, calculi and bladder capacity was subsequently recorded. Symptomatic ureteral NA remains a rare finding. To our knowledge we report the first pediatric case of ureteral NA in the English literature. Our limited experience suggests that sodium hyaluronate
instillation is a viable option in patients with symptomatic obstruction. Adam J. Rensing, Joel F. Koenig and Gino J. Vricella Division of Urologic Surgery and
Jennifer K. Sehn Department of Pathology and Immunology Washington University School of Medicine St. Louis, Missouri 1. Davis TA: Hamartoma of the urinary bladder. Northwest Med 1949; 48: 182. 2. Friedman NB and Kuhlenbeck H: Adenomatoid tumors of the bladder reproducing renal structures (nephrogenic adenomas). J Urol 1950; 64: 657. 3. Heidenreich A, Zirbes TK, Wolter S et al: Nephrogenic adenoma: a rare bladder tumor in children. Eur Urol 1999; 36: 348. 4. Doluoglu OG, Acarer EY, Yavuz A et al: Nephrogenic adenoma of the ureter. Rare Tumors 2012; 4: e28. 5. Campobasso P, Fasoli L and Dante S: Sodium hyaluronate in treatment of diffuse nephrogenic adenoma of the bladder in a child. J Pediatr Urol 2007; 3: 156.
