CASE REPORT
Nephrogenic Adenoma in a Urethral Diverticulum Harneet Gujral, MD,* Haiyang Chen, MD,Þ and Tanaz R. Ferzandi, MD, MA*þ
Abstract: Nephrogenic adenoma (NA) is a rare finding that represents metaplasia of the urothelium. We present a case of a 46-year-old woman who presented with a symptomatic anterior vaginal wall cyst that was found to be an NA within a urethral diverticulum. Although this remains an infrequently reported entity in the literature, prevalence has been shown to be higher in consecutive case series than what may be presumed by the rarity of case reports in clinical literature. Nephrogenic adenoma within a urethral diverticulum may represent an underrecognized entity which needs to be carefully distinguished from clear cell adenocarcinoma occurring within urethral diverticula. We discuss salient clinical features of NA occurring within a urethral diverticulum and describe a review of literature of published cases to date. Key Words: nephrogenic adenoma, urethral diverticulum (Female Pelvic Med Reconstr Surg 2014;20: e12Ye14) FIGURE 1. Transvaginal ultrasound demonstrating anterior vaginal wall cyst.
CASE A 46-year-old woman, gravida 3, para 3, presented with 1 year of urinary incontinence and discomfort related to a vaginal bulge. She denied any other associated symptoms such as dysuria, postvoid dribbling, or history of recurrent urinary tract infections. Her medical and surgical history was significant for a seizure disorder, psychiatric disease, postpartum tubal ligation, and spinal surgery. Physical examination was consistent with an anterior vaginal wall cyst. She reported symptoms consistent with mixed urinary incontinence but was a poor historian. Hence, urodynamic testing was done, which revealed predominant detrusor overactivity in addition to stress incontinence. A follow-up transvaginal ultrasound showed an anterior vaginal wall cyst measuring approximately 2.2 2.3 2.3 cm with central fluid demonstrating some low-level internal echoes, likely a Gartner cyst (Fig. 1). A magnetic resonance imaging was not performed as the mass was shown to be stable on ultrasound done at another institution, which was consistent with the physical examination findings of a discrete mass. After discussion with the patient, the decision was made to proceed with the excision. She was counseled that a midurethral sling for her stress incontinence would not be attempted given the overlapping dissection plane and risk for mesh erosion into the urethra if the sling was placed concomitantly. Operative findings were significant for a cyst that encompassed the vaginal introitus and extended to the bladder neck. After
From the *Department of Obstetrics and Gynecology, †Department of Pathology and Laboratory Medicine, and ‡Division of Urogynecology and Pelvic Reconstructive Surgery, Tufts Medical Center, Boston, MA. Reprints: Tanaz R. Ferzandi, MD, MA, Division of Urogynecology and Pelvic Reconstructive Surgery and Department of Obstetrics and Gynecology, Tufts Medical Center, 800 Washington St, #232, Boston, MA 02111. E-mail: [email protected]. The authors have declared they have no conflicts of interest Copyright * 2014 by Lippincott Williams & Wilkins DOI: 10.1097/SPV.0000000000000122
Female Pelvic Medicine & Reconstructive Surgery
&
initial circumferential dissection around the cyst, the mass was entered given lack of dissection planes. The cyst wall was noted to be adherent to the urethra. Dissection was complicated by entry into the urethral mucosa, leading to a 7-mm defect which was subsequently repaired and then reinforced with a small piece of Surgisis biologic graft given the lack of subepithelial fascia to accomplish a native tissue repair. Microscopic examination revealed urethral wall, consistent with a diverticulum, with flattened surface epithelium and tubules, cysts, and chronic inflammatory cells within the lamina propria (Fig. 2). The epithelium lining the tubules and cysts consisted of a single layer of bland flat or hobnail cells (nucleus of cell protrudes into lumen); some tubules were surrounded by a thickened and hyalinized basement membrane (Fig. 3). No mitotic figures were identified. The findings were consistent with nephrogenic adenoma (NA), which was confirmed by the
FIGURE 2. Section of diverticulum containing urethral wall with tubules (thick arrow) and cysts (thin arrow) within the lamina propria consistent with NA (hematoxylin-eosin, 40).
Volume 20, Number 6, November/December 2014
www.fpmrs.net
Copyright © 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited.
e1
Female Pelvic Medicine & Reconstructive Surgery
Gujral et al
FIGURE 3. Tubules lined by hobnail (thick arrow) and flat epithelial cells and surrounded by a thickened basement membrane (thin arrow) (hematoxylin-eosin, 400).
positive staining of the lining cells by immunohistochemical stains for cytokeratin, PAX8, and p504S.
DISCUSSION Nephrogenic adenoma is a rare finding that represents metaplasia of the urothelium. This entity was first described by Davis in 1949 and got its name ‘‘nehprogenic adenoma’’ by Friedman and Kuhlenbeck based on histological resemblance to renal tubules.1,2 Nephrogenic adenomas are more common in men than in women and most commonly occur in the bladder
&
Volume 20, Number 6, November/December 2014
(80%). They are also found in other ectopic sites including the urethra (15%), ureter (5%), and renal pelvis (G1%). Of the cases occurring in the female urethra, 26% are associated with a urethral diverticulum.3 The exact incidence of NA occurring within urethral diverticula in women is difficult to determine given the paucity of data. One case series of 90 consecutive female urethral diverticulectomy specimens done at a single institution found NA in 11% of total specimens.4 Outside the aforementioned case series, on our review of available literature, we were able to identify a total of 18 cases of NA within urethral diverticula in women (Table 1). Pathogenesis of NA is thought to be related to metaplastic change in the urothelium from chronic inflammation secondary to genitourinary trauma, prior surgery, renal calculi, or repeated instrumentation, although none of these risk factors were present in our patient.5 A recent study of NA in renal transplant recipients provided strong evidence of NAs being ectopic autografts from renal tubular cells being shed into the urinary tract.6 This has clinical relevance because NA stain positive for PAX-2, a renal transcription factor and an important feature which helps differentiate NA from other urothelial lesions.7 Histologic finding typically shows small- to medium-sized tubules surrounding a basement membrane in a band-like pattern. Immunohistochemistry is positive for PAX-2, AMACR, CD 10, epithelial membrane antigen, cytokeratin CK-7, cam 5.2, and acquporin-1.3 The clinical presentation can vary from a triad of dysuria, postvoid dribbling, and dyspareunia associated with urethral diverticula to nonspecific urinary complaints to being an incidental finding.3 Differential diagnosis of NA occurring inside
TABLE 1. Case Reports of NA in Female Urethral Diverticula Reference
Year
No. Patients
Age, y
Sex
Peterson and Matsumoto11
1978
1
40
F
Bhagavan et al10
1981
1
11Y78 (mean, 50)
M and F
Young and Scully5
1986
2
18Y75 (mean, 45)
M and F
Piazza et al12 Odze and Be´gin13
1987 1989
1 1
N/A 25
F F
Medeiros and Young14 Pamplona et al15 Miyake et al16 Vargas-Serrano et al17
1989 1990 1990 1994
5 1 1 1
31Y56 (mean, 38) N/A 39 36
F F F F
Summitt et al18 Klutke et al19
1994 1995
1 1
27 43
F F
Materne et al20 Paik and Lee21 Thomas et al4
1995 1997 2008
1 1 10
32 N/A 24Y78 (mean, 45)
F F F
Sidana et al22
2012
1
55
F
e2
www.fpmrs.net
Brief Summary/Treatment 3 d h/o pain, 2/2 infected diverticulum (4 3 2 cm) Case series of 8 cases of NA of the urinary tract; 1 pt had NA of the urinary diverticulum (sex not provided) Case series of 15 cases of NA of the urinary tract; 2 of these cases were NA in female urinary diverticula V Chronic slowly enlarging anterior vaginal mass with dyspareunia, diverticulum on examination V Perineal pain, diverticulum on examination 5 mo of frequency, urgency, intermittent dysuria with diverticulum on examination 4 wk h/o pelvic pressure and vaginal mass H/o recurrent UTIs, urethral diverticulum on examination V V Retrospective analysis of 90 female urethral diverticulectomy specimens; 10 specimens showed presence of NA 1 y of SUI, dysuria, frequency with diverticulum on examination; underwent diverticulectomy and midurethral sling placement * 2014 Lippincott Williams & Wilkins
Copyright © 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited.
Female Pelvic Medicine & Reconstructive Surgery
&
Volume 20, Number 6, November/December 2014
the urethral diverticulum includes other benign and malignant lesions occurring in the same anatomic location or within urethral diverticula. These include Gartner duct cysts, vaginal inclusion cysts, ectopic ureteroceles, endometriomas, Skene gland abscesses, and carcinomas. It is especially important to distinguish NA from clear cell adenocarcinoma which also has an association with urethral diverticula and may have focal similarities to NA on histologic finding.4,8,9 In the previously mentioned case series of 90 urethral diverticula, 6% were noted to have invasive adenocarcinoma.4 Whether NA is a premalignant condition has been raised multiple times in the literature. However, the burden of evidence suggests that NA represents a true benign lesion, although local recurrence has been described.5,10 The recommendation for management is resection. Nephrogenic adenomas within urethral diverticula are easily amenable to transvaginal approach and diverticulectomy as was the case in our patient. It is important to communicate the size and location of the mass with the pathologist. If only a small biopsy is taken, a description of the entire mass as well as pertinent history findings of mucosal irritation or immunosuppression may aid the pathologist in differentiating between NA and a malignancy. Because NAs have a tendency of symptomatic recurrence, routine follow-up cystoscopy, initially every 3 months and after a disease-free interval every 6 to 12 months, can be considered for surveillance.3,10 In conclusion, NA within urethral diverticula represents a potentially under-recognized benign lesion with a tendency for local recurrence. It may mimic clear cell carcinomas; hence, its knowledge and careful pathologic analysis of surgical specimen remains paramount in its identification and appropriate treatment. REFERENCES 1. Davis TA. Hamartoma of the urinary bladder. Northwest Med 1949;48(3):182Y185. 2. Friedman NB, Kuhlenbeck H. Adenomatoid tumors of the bladder reproducing renal structures (nephrogenic adenomas). J Urol 1950;64(5):657Y670. 3. Amin W, Parwani AV. Nephrogenic adenoma. Pathol Res Pract 2010;206(10):659Y662. 4. Thomas AA, Rackley RR, Lee U, et al. Urethral diverticula in 90 female patients: a study with emphasis on neoplastic alterations. J Urol 2008;180(6):2463Y2467. 5. Young RH, Scully RE. Nephrogenic adenoma. A report of 15 cases, review of the literature, and comparison with clear cell adenocarcinoma of the urinary tract. Am J Surg Pathol 1986;10(4):268Y275.
* 2014 Lippincott Williams & Wilkins
NA in a Urethral Diverticulum
6. Mazal PR, Schaufler R, Altenhuber-Mu¨ller R, et al. Derivation of nephrogenic adenomas from renal tubular cells in kidney-transplant recipients. N Engl J Med 2002;347(9):653Y659. 7. Tong G-X, Melamed J, Mansukhani M, et al. PAX2: a reliable marker for nephrogenic adenoma. Mod Pathol 2006;19(3):356Y363. 8. Oliva E, Young RH. Clear cell adenocarcinoma of the urethra: a clinicopathologic analysis of 19 cases. Mod Pathol 1996;9(5):513Y520. 9. Gilcrease MZ, Delgado R, Vuitch F, et al. Clear cell adenocarcinoma and nephrogenic adenoma of the urethra and urinary bladder: a histopathologic and immunohistochemical comparison. Hum Pathol 1998;29(12):1451Y1456. 10. Bhagavan BS, Tiamson EM, Wenk RE, et al. Nephrogenic adenoma of the urinary bladder and urethra. Hum Pathol 1981;12(10):907Y916. 11. Peterson LJ, Matsumoto LM. Nephrogenic adenoma in urethral diverticulum. Urology 1978;11(2):193Y195. 12. Piazza R, Aragona F, Pizzarella M, et al. Nephrogenic adenoma in urethral diverticulum: an unusual finding. Urol Int 1987;42(1):69Y70. 13. Odze R, Be´gin LR. Tubular adenomatous metaplasia (nephrogenic adenoma) of the female urethra. Int J Gynecol Pathol 1989;8(4):374Y380. 14. Medeiros LJ, Young RH. Nephrogenic adenoma arising in urethral diverticula. A report of five cases. Arch Pathol Lab Med 1989;113(2):125Y128. 15. Pamplona M, Paniagua P, Gimeno F, et al. Nephrogenic adenoma in urethral diverticulum in women [in Spanish]. Actas Urol Esp 1990;14(4):277Y278. 16. Miyake O, Hara T, Matsumiya K, et al. A case of nephrogenic adenoma in the female urethral diverticulum [in Japanese]. Hinyokika Kiyo 1990;36(10):1189Y1192. 17. Vargas-Serrano B, Rodriguez-Romero R, Burgos F, et al. Nephrogenic adenoma in urethral diverticulum in a woman. J Clin Ultrasound 1994;22(4):268Y270. 18. Summitt RL Jr, Murrmann SG, Flax SD. Nephrogenic adenoma in a urethral diverticulum. A case report. J Reprod Med 1994;39(6):473Y476. 19. Klutke CG, Akdman EI, Brown JJ. Nephrogenic adenoma arising from a urethral diverticulum: magnetic resonance features. Urology 1995;45(2):323Y325. 20. Materne R, Dardenne AN, Opsomer RJ, et al. Apropos of a case of nephrogenic adenoma in a urethral diverticulum in a woman [in French]. Acta Urol Belg 1995;63(4):13Y18. 21. Paik SS, Lee JD. Nephrogenic adenoma arising in an urethral diverticulum. Br J Urol 1997;80(1):150. 22. Sidana A, Zhai QJ, Mahdy A. Nephrogenic adenoma in a urethral diverticulum. Urology 2012;80(2):e21Ye22.
www.fpmrs.net
Copyright © 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited.
e3
Nephrogenic Adenoma in a Urethral Diverticulum Harneet Gujral, MD,* Haiyang Chen, MD,Þ and Tanaz R. Ferzandi, MD, MA*þ
Abstract: Nephrogenic adenoma (NA) is a rare finding that represents metaplasia of the urothelium. We present a case of a 46-year-old woman who presented with a symptomatic anterior vaginal wall cyst that was found to be an NA within a urethral diverticulum. Although this remains an infrequently reported entity in the literature, prevalence has been shown to be higher in consecutive case series than what may be presumed by the rarity of case reports in clinical literature. Nephrogenic adenoma within a urethral diverticulum may represent an underrecognized entity which needs to be carefully distinguished from clear cell adenocarcinoma occurring within urethral diverticula. We discuss salient clinical features of NA occurring within a urethral diverticulum and describe a review of literature of published cases to date. Key Words: nephrogenic adenoma, urethral diverticulum (Female Pelvic Med Reconstr Surg 2014;20: e12Ye14) FIGURE 1. Transvaginal ultrasound demonstrating anterior vaginal wall cyst.
CASE A 46-year-old woman, gravida 3, para 3, presented with 1 year of urinary incontinence and discomfort related to a vaginal bulge. She denied any other associated symptoms such as dysuria, postvoid dribbling, or history of recurrent urinary tract infections. Her medical and surgical history was significant for a seizure disorder, psychiatric disease, postpartum tubal ligation, and spinal surgery. Physical examination was consistent with an anterior vaginal wall cyst. She reported symptoms consistent with mixed urinary incontinence but was a poor historian. Hence, urodynamic testing was done, which revealed predominant detrusor overactivity in addition to stress incontinence. A follow-up transvaginal ultrasound showed an anterior vaginal wall cyst measuring approximately 2.2 2.3 2.3 cm with central fluid demonstrating some low-level internal echoes, likely a Gartner cyst (Fig. 1). A magnetic resonance imaging was not performed as the mass was shown to be stable on ultrasound done at another institution, which was consistent with the physical examination findings of a discrete mass. After discussion with the patient, the decision was made to proceed with the excision. She was counseled that a midurethral sling for her stress incontinence would not be attempted given the overlapping dissection plane and risk for mesh erosion into the urethra if the sling was placed concomitantly. Operative findings were significant for a cyst that encompassed the vaginal introitus and extended to the bladder neck. After
From the *Department of Obstetrics and Gynecology, †Department of Pathology and Laboratory Medicine, and ‡Division of Urogynecology and Pelvic Reconstructive Surgery, Tufts Medical Center, Boston, MA. Reprints: Tanaz R. Ferzandi, MD, MA, Division of Urogynecology and Pelvic Reconstructive Surgery and Department of Obstetrics and Gynecology, Tufts Medical Center, 800 Washington St, #232, Boston, MA 02111. E-mail: [email protected]. The authors have declared they have no conflicts of interest Copyright * 2014 by Lippincott Williams & Wilkins DOI: 10.1097/SPV.0000000000000122
Female Pelvic Medicine & Reconstructive Surgery
&
initial circumferential dissection around the cyst, the mass was entered given lack of dissection planes. The cyst wall was noted to be adherent to the urethra. Dissection was complicated by entry into the urethral mucosa, leading to a 7-mm defect which was subsequently repaired and then reinforced with a small piece of Surgisis biologic graft given the lack of subepithelial fascia to accomplish a native tissue repair. Microscopic examination revealed urethral wall, consistent with a diverticulum, with flattened surface epithelium and tubules, cysts, and chronic inflammatory cells within the lamina propria (Fig. 2). The epithelium lining the tubules and cysts consisted of a single layer of bland flat or hobnail cells (nucleus of cell protrudes into lumen); some tubules were surrounded by a thickened and hyalinized basement membrane (Fig. 3). No mitotic figures were identified. The findings were consistent with nephrogenic adenoma (NA), which was confirmed by the
FIGURE 2. Section of diverticulum containing urethral wall with tubules (thick arrow) and cysts (thin arrow) within the lamina propria consistent with NA (hematoxylin-eosin, 40).
Volume 20, Number 6, November/December 2014
www.fpmrs.net
Copyright © 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited.
e1
Female Pelvic Medicine & Reconstructive Surgery
Gujral et al
FIGURE 3. Tubules lined by hobnail (thick arrow) and flat epithelial cells and surrounded by a thickened basement membrane (thin arrow) (hematoxylin-eosin, 400).
positive staining of the lining cells by immunohistochemical stains for cytokeratin, PAX8, and p504S.
DISCUSSION Nephrogenic adenoma is a rare finding that represents metaplasia of the urothelium. This entity was first described by Davis in 1949 and got its name ‘‘nehprogenic adenoma’’ by Friedman and Kuhlenbeck based on histological resemblance to renal tubules.1,2 Nephrogenic adenomas are more common in men than in women and most commonly occur in the bladder
&
Volume 20, Number 6, November/December 2014
(80%). They are also found in other ectopic sites including the urethra (15%), ureter (5%), and renal pelvis (G1%). Of the cases occurring in the female urethra, 26% are associated with a urethral diverticulum.3 The exact incidence of NA occurring within urethral diverticula in women is difficult to determine given the paucity of data. One case series of 90 consecutive female urethral diverticulectomy specimens done at a single institution found NA in 11% of total specimens.4 Outside the aforementioned case series, on our review of available literature, we were able to identify a total of 18 cases of NA within urethral diverticula in women (Table 1). Pathogenesis of NA is thought to be related to metaplastic change in the urothelium from chronic inflammation secondary to genitourinary trauma, prior surgery, renal calculi, or repeated instrumentation, although none of these risk factors were present in our patient.5 A recent study of NA in renal transplant recipients provided strong evidence of NAs being ectopic autografts from renal tubular cells being shed into the urinary tract.6 This has clinical relevance because NA stain positive for PAX-2, a renal transcription factor and an important feature which helps differentiate NA from other urothelial lesions.7 Histologic finding typically shows small- to medium-sized tubules surrounding a basement membrane in a band-like pattern. Immunohistochemistry is positive for PAX-2, AMACR, CD 10, epithelial membrane antigen, cytokeratin CK-7, cam 5.2, and acquporin-1.3 The clinical presentation can vary from a triad of dysuria, postvoid dribbling, and dyspareunia associated with urethral diverticula to nonspecific urinary complaints to being an incidental finding.3 Differential diagnosis of NA occurring inside
TABLE 1. Case Reports of NA in Female Urethral Diverticula Reference
Year
No. Patients
Age, y
Sex
Peterson and Matsumoto11
1978
1
40
F
Bhagavan et al10
1981
1
11Y78 (mean, 50)
M and F
Young and Scully5
1986
2
18Y75 (mean, 45)
M and F
Piazza et al12 Odze and Be´gin13
1987 1989
1 1
N/A 25
F F
Medeiros and Young14 Pamplona et al15 Miyake et al16 Vargas-Serrano et al17
1989 1990 1990 1994
5 1 1 1
31Y56 (mean, 38) N/A 39 36
F F F F
Summitt et al18 Klutke et al19
1994 1995
1 1
27 43
F F
Materne et al20 Paik and Lee21 Thomas et al4
1995 1997 2008
1 1 10
32 N/A 24Y78 (mean, 45)
F F F
Sidana et al22
2012
1
55
F
e2
www.fpmrs.net
Brief Summary/Treatment 3 d h/o pain, 2/2 infected diverticulum (4 3 2 cm) Case series of 8 cases of NA of the urinary tract; 1 pt had NA of the urinary diverticulum (sex not provided) Case series of 15 cases of NA of the urinary tract; 2 of these cases were NA in female urinary diverticula V Chronic slowly enlarging anterior vaginal mass with dyspareunia, diverticulum on examination V Perineal pain, diverticulum on examination 5 mo of frequency, urgency, intermittent dysuria with diverticulum on examination 4 wk h/o pelvic pressure and vaginal mass H/o recurrent UTIs, urethral diverticulum on examination V V Retrospective analysis of 90 female urethral diverticulectomy specimens; 10 specimens showed presence of NA 1 y of SUI, dysuria, frequency with diverticulum on examination; underwent diverticulectomy and midurethral sling placement * 2014 Lippincott Williams & Wilkins
Copyright © 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited.
Female Pelvic Medicine & Reconstructive Surgery
&
Volume 20, Number 6, November/December 2014
the urethral diverticulum includes other benign and malignant lesions occurring in the same anatomic location or within urethral diverticula. These include Gartner duct cysts, vaginal inclusion cysts, ectopic ureteroceles, endometriomas, Skene gland abscesses, and carcinomas. It is especially important to distinguish NA from clear cell adenocarcinoma which also has an association with urethral diverticula and may have focal similarities to NA on histologic finding.4,8,9 In the previously mentioned case series of 90 urethral diverticula, 6% were noted to have invasive adenocarcinoma.4 Whether NA is a premalignant condition has been raised multiple times in the literature. However, the burden of evidence suggests that NA represents a true benign lesion, although local recurrence has been described.5,10 The recommendation for management is resection. Nephrogenic adenomas within urethral diverticula are easily amenable to transvaginal approach and diverticulectomy as was the case in our patient. It is important to communicate the size and location of the mass with the pathologist. If only a small biopsy is taken, a description of the entire mass as well as pertinent history findings of mucosal irritation or immunosuppression may aid the pathologist in differentiating between NA and a malignancy. Because NAs have a tendency of symptomatic recurrence, routine follow-up cystoscopy, initially every 3 months and after a disease-free interval every 6 to 12 months, can be considered for surveillance.3,10 In conclusion, NA within urethral diverticula represents a potentially under-recognized benign lesion with a tendency for local recurrence. It may mimic clear cell carcinomas; hence, its knowledge and careful pathologic analysis of surgical specimen remains paramount in its identification and appropriate treatment. REFERENCES 1. Davis TA. Hamartoma of the urinary bladder. Northwest Med 1949;48(3):182Y185. 2. Friedman NB, Kuhlenbeck H. Adenomatoid tumors of the bladder reproducing renal structures (nephrogenic adenomas). J Urol 1950;64(5):657Y670. 3. Amin W, Parwani AV. Nephrogenic adenoma. Pathol Res Pract 2010;206(10):659Y662. 4. Thomas AA, Rackley RR, Lee U, et al. Urethral diverticula in 90 female patients: a study with emphasis on neoplastic alterations. J Urol 2008;180(6):2463Y2467. 5. Young RH, Scully RE. Nephrogenic adenoma. A report of 15 cases, review of the literature, and comparison with clear cell adenocarcinoma of the urinary tract. Am J Surg Pathol 1986;10(4):268Y275.
* 2014 Lippincott Williams & Wilkins
NA in a Urethral Diverticulum
6. Mazal PR, Schaufler R, Altenhuber-Mu¨ller R, et al. Derivation of nephrogenic adenomas from renal tubular cells in kidney-transplant recipients. N Engl J Med 2002;347(9):653Y659. 7. Tong G-X, Melamed J, Mansukhani M, et al. PAX2: a reliable marker for nephrogenic adenoma. Mod Pathol 2006;19(3):356Y363. 8. Oliva E, Young RH. Clear cell adenocarcinoma of the urethra: a clinicopathologic analysis of 19 cases. Mod Pathol 1996;9(5):513Y520. 9. Gilcrease MZ, Delgado R, Vuitch F, et al. Clear cell adenocarcinoma and nephrogenic adenoma of the urethra and urinary bladder: a histopathologic and immunohistochemical comparison. Hum Pathol 1998;29(12):1451Y1456. 10. Bhagavan BS, Tiamson EM, Wenk RE, et al. Nephrogenic adenoma of the urinary bladder and urethra. Hum Pathol 1981;12(10):907Y916. 11. Peterson LJ, Matsumoto LM. Nephrogenic adenoma in urethral diverticulum. Urology 1978;11(2):193Y195. 12. Piazza R, Aragona F, Pizzarella M, et al. Nephrogenic adenoma in urethral diverticulum: an unusual finding. Urol Int 1987;42(1):69Y70. 13. Odze R, Be´gin LR. Tubular adenomatous metaplasia (nephrogenic adenoma) of the female urethra. Int J Gynecol Pathol 1989;8(4):374Y380. 14. Medeiros LJ, Young RH. Nephrogenic adenoma arising in urethral diverticula. A report of five cases. Arch Pathol Lab Med 1989;113(2):125Y128. 15. Pamplona M, Paniagua P, Gimeno F, et al. Nephrogenic adenoma in urethral diverticulum in women [in Spanish]. Actas Urol Esp 1990;14(4):277Y278. 16. Miyake O, Hara T, Matsumiya K, et al. A case of nephrogenic adenoma in the female urethral diverticulum [in Japanese]. Hinyokika Kiyo 1990;36(10):1189Y1192. 17. Vargas-Serrano B, Rodriguez-Romero R, Burgos F, et al. Nephrogenic adenoma in urethral diverticulum in a woman. J Clin Ultrasound 1994;22(4):268Y270. 18. Summitt RL Jr, Murrmann SG, Flax SD. Nephrogenic adenoma in a urethral diverticulum. A case report. J Reprod Med 1994;39(6):473Y476. 19. Klutke CG, Akdman EI, Brown JJ. Nephrogenic adenoma arising from a urethral diverticulum: magnetic resonance features. Urology 1995;45(2):323Y325. 20. Materne R, Dardenne AN, Opsomer RJ, et al. Apropos of a case of nephrogenic adenoma in a urethral diverticulum in a woman [in French]. Acta Urol Belg 1995;63(4):13Y18. 21. Paik SS, Lee JD. Nephrogenic adenoma arising in an urethral diverticulum. Br J Urol 1997;80(1):150. 22. Sidana A, Zhai QJ, Mahdy A. Nephrogenic adenoma in a urethral diverticulum. Urology 2012;80(2):e21Ye22.
www.fpmrs.net
Copyright © 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited.
e3
