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Bilateral fibroepithelial polyps of ureter in a child
PEDIATRIC UROLOGY
BILATERAL FIBROEPITHELIAL POLYPS OF URETER IN A CHILD FRANCIS E BARTONE, M.D. SONNY L. JOHANSSON, M.D. RODNEY J. MARKIN, M.D. THOMAS J. IMRAY, M.D. From the Department of Surgery, Section of Urology, and the Departments of Pathology and Radiology, University of Nebraska Medieal Center, Omaha, Nebraska
1 1"t ~CT--Presented here is the ]irst case of bilateral ureteral polyps in a patient under eighteen ~ars of oftage, with vivid colored intraoperative photographs. The importance of careful identi]icaoJ the base of the polyp to reduce operative morbidity and the necessity oif ureteral reanastomoN }ather than simple excision of the polyp in children is emphasized.
polyps in patients under the age of ~ieighteen years are rare with approximately 16 ~4:'+I ~;:~aseshavir g been reported in the English literanajority of these polyps are fipolyps. Polyps represent 0.5-4 all eases of hydronephrosis in eh further emphasizes their rarease reports of unilateral polyps mblished recently; however, we rst ease of bilateral ureteral polyps [ the second ease of bilateral polyps n the English literature. 4 In our of this patient we note several imeiples previously mentioned but sized. Case Report ~iiiA tweIve-year-old Caucasian male with a hisJrrent episodes of "pyelonephritis" at another institution and was susave bilateral ureteral polyps assoobstruction of the right ureter. The therefore referred for definitive His physieal examination ineluding 1re, was within normal limits. Uriurine culture were normal and :inine was 0.7 mg/dL. An intrave-
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JUNE 1990
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VOLUME XXXV, NUMBEB 6
nous pyelogram e o n f i r m e d t h e suspected diagnosis (Fig. 1). The p a t i e n t underwent a DPTA renal scan with Lasix. The scan was reported as revealing bilateral upper ureteral obstruction being more severe on the right side, He underwent exploration of the right upper ureter through a flank approach. Approximately 1 em from the ureteropelvic junction a firm hard area was palpated. A longitudinal ureterotomy was made a n d several finger-like polyps extruded forth (Fig. 2). The base of the polyp was identified. Its size encompassed the major part of the ureter. A 0.8 em segment of the ureter was removed a n d ureteral continuity reestablished with an u n s t e n t e d end-to-end anastomosis. Eight days postoperatively his n e p h r o s t o m y tube w a s r e m o v e d after a nephrostogram confirmed p r o m p t drainage. Several months later, because of previous evidence of upper left ureteral obstruction along with recurrent episodes of pain he underwent surgical exploration of t h e left ureter via a flank incision. A ureterotomy w a s performed at the presumed location of the base of the polyp. The polyp was identified and extended distally for 6 era. This necessitated a 4-era ureterostomy. The base was easily excised a n d the entire polyp removed. The polyp consisted of a Gem long 519
FIGURE 1. Intravenous pyelogram. Almost complete obstruction on right and irregular defects on left compatible with ureteral polyps.
FIGURE2. Intraoperative photographs of right ureter at inception o] ureterostomy. (A) Beginning protrusion of polyp, (B) Protrusion of multiple strands,
single strand of a wormlike projection measuring 2 m m in diameter. It was noted that the polyp was proximal to its base (Fig. 3). Because the ureter was very narrow and did not completely surround a 5 F catheter, a Davis intubated ureterostomy was done over an 8 F Silastie tube. A subsequent pyelogram s e v e r n weeks after the removal of the tube showed normal excretion of contrast material and no evidence of obstruction (Fig. 4). The present bilateral ureterN lesions have the characteristics of fibroepitheliN polyps and were comprised of a central party eollagenized fibrovaseular core covered by n o r m a l urothelium. Focal erosion was present.
Lebowitz, and Carroll series. 5 Hematuria m a y also be a presenting symptom but is less comm o n in children than adults 1,~,s,°-~3 and was not present in our patient. Our patient had repeated unexplained episodes of colicky pain associated with bacteriuria. It has been noted by
Comment Our patient presented with intermittent bilateral colicky pain which is a c o m m o n clinical presentation in children and adults with uret e r n polyps and is associated w i t h periodic episodes of distention of the renal pelvis and ureter. 4 This was so in 8 of 11 eases in the Berger,
showing single strand of 2-ram polyp,
520
UROLOGY / JUNE t990
FmURE 3.
Intraoperative photograph oJ left ureteli
/ VOLUME XXXV, NUMBEI~6
FIGURE4.
intravenous pyelogram. Excellent postoperative result.
others that symptoms can be present for extended periods of time prior to the diagnosis. Indeed, in the series by Williams et al. ~ the clinical symptoms had been present for five and one-half years on the average. The radiographic features of ureteral polyps are varied, but fall into two categories. The first is that of long slender cylindrical masses within the ureter. They are more frequently found in the proximal ureter and may even arise in the renal pelvis or a renal ealix. The point of connection to the wall of the ureter is by a thin stalk, and the demonstration of this stalk is inconsistent. The point of attachment may be inferred by changes in position of the polyp during the examination. The second type of polyp is often shorter, wider, and more likely to cause obstruction. It has multiple filiform projections ,extending from the main body of the polyp. 8 The diagnosis of ureteral polyps can usually be made with a relative degree of certainty from the intravenous urogram. If an obstruct-
UROLOGY
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JUNE 1990
/
VOLUME XXXV, NUMBER 6
ing polyp is present, attention is directed to the site of the lesion. Polyps are almost always longer than they are wide and may be bulbous on the end. There is often narrowing of the ureter at the site of the attachment of the stalk; however, this is a variable finding. Even in children, high-dose intravenous urography may be utilized to maximally distend the ureters thus enhancing detection. Fluoroscopy of the ureter during intravenous urography with appropriate spot filming can increase the detection of polyps on intravenous urography and assist in delineating the site of attachment. 14 Ureteral polyps may be quite long, even prolapsing into the bladder. They may change position during intravenous urography, further confirming the diagnosis. Retrograde pyeloureterography may be necessary to pinpoint the site of attachment of the polyp. Retrograde displacement of the polyp during ureterography has been documented in literature? O t h e r considerations in the differential diagnosis of interureteric masses include blood clot, nonopaque calculi, and ureteral tumors. The latter are almost nonexistent in children. In a literature review, we could find no case of ureteral tumors in children and only 6 eases of renal pelvic tumors. This r e v i e w is from 1943.15a~ Blood clots commonly form a east of the ureter and can be remarkably similar in appearance to a ureteral polyp. A repeat examination will show passage or lysis of the clot, and multiple films during a single examination often show passage of the clot down the ureter since it is not attached to the ureteral wall. Calculi are rare in children, seldom over a centimeter in length, and are not filiform or wormlike in appearance. They are nonpliable on fluoroscopy and usually cause some degree of ureteral spasm with ureteral narrowing just distal to the calculus. Ureteral polyps, on the other hand, usually cause ureteral enlargement below and around the body of the polyp. Uric acid ealculi ean easily be differentiated from polyps or clot by non.contrast computer tomography (CT) since uric acid calculi have high attenuation in the range of 75-85 Hounsfield units (HU) whereas polyps have attenuation in the soft tissue range, 30-40 HU. L7.18 In children the differential diagnosis usually is between ureteropelvic junction obstruction and ureteral polyps. One of the clues supporting the diagnosis of fibroepithelial polyps is the faet that tlae renal pelvis funnels well into a dependent ureteropelvic junction in patients with
521
polyps. This is in contrast to patients with classic ureteropelvic junction obstruction. Patients with polyps never have a lucent defect caused by crossing fibrous or vascular bands. 1 The preponderance of male patients is 3 to 1 in the literature.S There also seems to be a preponderance for the left side, and the upper ureter is usually the site of the polyp base.1-~2 Many clinical, radiologic, morphologic, and surgical aspects of fibroepithelial polyps of the ureter have been reported previously, but there are two points that are emphasized in the present ease. First it is important to locate the base of the polyp by r a d i o g r a p h i c means; if identifieation cannot be made by intravenous urography, retrograde and/or antegrade pyelography should be performed. The ureteral polyp on the left side was located proximal to its base and a 4-era ureterostomy w a s necessary to locate and excise it. The morbidity would have been much less had we known the position of its base prior to operation. As far as we know, this is the first instance of a polyp being proximal to its base without retrograde pyelography being performed prior to the operation. It is also the first instanee in which a small polyt~,,caused obstruction by retrograde bu.nching. It is likely that the intermittent obstruction of the left ureter was eaused by retrograde "bunching" of the polyp as it only measured 2 m m in diameter and had a very narrow base. The second observation that requires emphasis in the pediatric eases is a preponderance of instances in which a ureteroureterostomy or ureteropyelostomy is necessary, for removal of the polyp alone would leave an obstructing base. In }he more recent adult literature, excision of the polyp base was all that was necessary. When ,operating on children, one should be prepared to excise the entire segment of the ureter where the insertion of the polyp base is located. This was necessary in our ease on the right side and in eases reported by others. L9-13 The etiology of ureteral polyps is unknown, but because they are present at an early age and seldom show evidence of infection, a developmental defect has been considered, s This is supported b y l ease in which a ureteral polyp was diagnosed in a newborn. 10 Histologically, ureteral polyps are composed of a fibrovaseular core, covered by a thin oneto-two-cell thick urothelium. This is the aPpearance of fibroepithelial polyps of the ureter, I generally encountered in the literature. 5 6,,1 3 In previously examining five other polyps, urothe522
lial hyperplasia was present in two, inflammation of varying degree in four, hemorrhage in all, and ureteritis cystiea in one. Naucler, e t a l . 6 reported a constriction of the polyp base. This eonstrietion is supposed t o identify the polyp base. We were not able to identify this eonstrietion on either side, and i t has not been mentioned in other reports suggesting that the phenomenon of constriction i s not common. The prognosis of ureteral polyps is exeellent and recurrenees have not been reported in s p i t e of observations of up to fifteen years. 4,5 Geisinger Clinic; Danville, Pennsylvania 17822::; (DR. BARTONE) ' References 1. Macksood MJ, Roth DR, Chang CH, and Perlmutter AD: Benign fibroepitheliai polyps as a eause of intermittent u r e t e r o , pelvie junction obstruetion in a child: a ease report and review of the literature, J Urol 134:951 (1985), 2. Williams JI, and Kenawi MM: The prognosis of pelviure* teric obstruetion in childhood: a review of 190 eases, Fur Uro! 57 (1976). 3. Johnston JD, Evans JP, Glassberg K1, and Shapiro SR'. Pelvic hydronephrosis in children: a review of 219 personal cases;: ] Urol 117:97 (1977). 4. Debruyne FMJ, Moonen WA, Daenekindt AA, and Delaere KPJ~ FibroepitheliaI polyp of ureter, Urology 16:355 (1980). 5. Berger RM, Lebowitz JM, and Carroll PA: Ureteral polyp~ presenting as ureteropelvie junetion obstruction in children, J Urol 128:805 (1982). 6. Naucler J, Johansson SL, Nilson AE, and Pettersson S: Fi~ broepithelial polyps of the ureter, Scand J Urol Nephrol 17:379
(1983). 7. Williams PR, Feggetter J, Miller I1A, and Wiekham JEA: The diagnosis and management of benign fibrous ureterie polyps, Br J Urol 52:253 (1980). 8. Banner MP, and Polleek HM: Fibrous ureteral polyps, Ha, diology 130:73 (1979). 9. Eilenberg J, Serry W, and Cole A: Multiple fibroepithelial polyps in the pediatric age group: ease report, J Urot 117:793 (1977). 1O. Schulman CC: Ureterie polyp as a cause of hydronephrosis in ehfldhood, J Pediatr Surg 13:537 (1978). 11. Thorup J, Pedersen PV, and Clausen N: Benign nretera! polyp as a cause of intermittent hydr0nephrosis in a child, J Ur0t 126:796 (1977). 12. Roodhooft AM, Gentens P, and Van Aeker Kj: Benign urea, teral fibrous polyp as a cause of obstruction in children, Pediai!: Rad 15:429 (1985). 13. Musselman P, and Kay It: The spectrum of urinary fi" broepithelial polyps in children, J Urol 136:429 (1985). 14. Hughes FA III, and Davis CS: Multiple benign ureteral fi~ brous polyps, AJR 126:723 (1976), 15. Schlapik D: Papillary carcinoma of the kidney in c h i l d hood, Urol Cutan Rev 47:183 (1943). 16. Koyanagi T, et ah Transitional eelI earcinoma of renai pelvis in an infant, J Urol i i 3 : 1 1 4 (!975). 171 Parienty RA, et ah DiagnOstic value of CT numbers ifi: pelvoca!yeeal filling defects, Radiology 145:743 (1982). 18. Pollack HM, et al Computed tomography of renal pelvi~ filling defect, Radiology 138:645 (1981). 19. Soderdahl DW, and Sehuster SR: Benign ureteral polyp in" the newborn, JAMA 207:1714 (1969).
UROLOGY
/
JUNE 1990
/
VOLUME XXXV, NUMBER 6i~
BILATERAL FIBROEPITHELIAL POLYPS OF URETER IN A CHILD FRANCIS E BARTONE, M.D. SONNY L. JOHANSSON, M.D. RODNEY J. MARKIN, M.D. THOMAS J. IMRAY, M.D. From the Department of Surgery, Section of Urology, and the Departments of Pathology and Radiology, University of Nebraska Medieal Center, Omaha, Nebraska
1 1"t ~CT--Presented here is the ]irst case of bilateral ureteral polyps in a patient under eighteen ~ars of oftage, with vivid colored intraoperative photographs. The importance of careful identi]icaoJ the base of the polyp to reduce operative morbidity and the necessity oif ureteral reanastomoN }ather than simple excision of the polyp in children is emphasized.
polyps in patients under the age of ~ieighteen years are rare with approximately 16 ~4:'+I ~;:~aseshavir g been reported in the English literanajority of these polyps are fipolyps. Polyps represent 0.5-4 all eases of hydronephrosis in eh further emphasizes their rarease reports of unilateral polyps mblished recently; however, we rst ease of bilateral ureteral polyps [ the second ease of bilateral polyps n the English literature. 4 In our of this patient we note several imeiples previously mentioned but sized. Case Report ~iiiA tweIve-year-old Caucasian male with a hisJrrent episodes of "pyelonephritis" at another institution and was susave bilateral ureteral polyps assoobstruction of the right ureter. The therefore referred for definitive His physieal examination ineluding 1re, was within normal limits. Uriurine culture were normal and :inine was 0.7 mg/dL. An intrave-
/
JUNE 1990
/
VOLUME XXXV, NUMBEB 6
nous pyelogram e o n f i r m e d t h e suspected diagnosis (Fig. 1). The p a t i e n t underwent a DPTA renal scan with Lasix. The scan was reported as revealing bilateral upper ureteral obstruction being more severe on the right side, He underwent exploration of the right upper ureter through a flank approach. Approximately 1 em from the ureteropelvic junction a firm hard area was palpated. A longitudinal ureterotomy was made a n d several finger-like polyps extruded forth (Fig. 2). The base of the polyp was identified. Its size encompassed the major part of the ureter. A 0.8 em segment of the ureter was removed a n d ureteral continuity reestablished with an u n s t e n t e d end-to-end anastomosis. Eight days postoperatively his n e p h r o s t o m y tube w a s r e m o v e d after a nephrostogram confirmed p r o m p t drainage. Several months later, because of previous evidence of upper left ureteral obstruction along with recurrent episodes of pain he underwent surgical exploration of t h e left ureter via a flank incision. A ureterotomy w a s performed at the presumed location of the base of the polyp. The polyp was identified and extended distally for 6 era. This necessitated a 4-era ureterostomy. The base was easily excised a n d the entire polyp removed. The polyp consisted of a Gem long 519
FIGURE 1. Intravenous pyelogram. Almost complete obstruction on right and irregular defects on left compatible with ureteral polyps.
FIGURE2. Intraoperative photographs of right ureter at inception o] ureterostomy. (A) Beginning protrusion of polyp, (B) Protrusion of multiple strands,
single strand of a wormlike projection measuring 2 m m in diameter. It was noted that the polyp was proximal to its base (Fig. 3). Because the ureter was very narrow and did not completely surround a 5 F catheter, a Davis intubated ureterostomy was done over an 8 F Silastie tube. A subsequent pyelogram s e v e r n weeks after the removal of the tube showed normal excretion of contrast material and no evidence of obstruction (Fig. 4). The present bilateral ureterN lesions have the characteristics of fibroepitheliN polyps and were comprised of a central party eollagenized fibrovaseular core covered by n o r m a l urothelium. Focal erosion was present.
Lebowitz, and Carroll series. 5 Hematuria m a y also be a presenting symptom but is less comm o n in children than adults 1,~,s,°-~3 and was not present in our patient. Our patient had repeated unexplained episodes of colicky pain associated with bacteriuria. It has been noted by
Comment Our patient presented with intermittent bilateral colicky pain which is a c o m m o n clinical presentation in children and adults with uret e r n polyps and is associated w i t h periodic episodes of distention of the renal pelvis and ureter. 4 This was so in 8 of 11 eases in the Berger,
showing single strand of 2-ram polyp,
520
UROLOGY / JUNE t990
FmURE 3.
Intraoperative photograph oJ left ureteli
/ VOLUME XXXV, NUMBEI~6
FIGURE4.
intravenous pyelogram. Excellent postoperative result.
others that symptoms can be present for extended periods of time prior to the diagnosis. Indeed, in the series by Williams et al. ~ the clinical symptoms had been present for five and one-half years on the average. The radiographic features of ureteral polyps are varied, but fall into two categories. The first is that of long slender cylindrical masses within the ureter. They are more frequently found in the proximal ureter and may even arise in the renal pelvis or a renal ealix. The point of connection to the wall of the ureter is by a thin stalk, and the demonstration of this stalk is inconsistent. The point of attachment may be inferred by changes in position of the polyp during the examination. The second type of polyp is often shorter, wider, and more likely to cause obstruction. It has multiple filiform projections ,extending from the main body of the polyp. 8 The diagnosis of ureteral polyps can usually be made with a relative degree of certainty from the intravenous urogram. If an obstruct-
UROLOGY
/
JUNE 1990
/
VOLUME XXXV, NUMBER 6
ing polyp is present, attention is directed to the site of the lesion. Polyps are almost always longer than they are wide and may be bulbous on the end. There is often narrowing of the ureter at the site of the attachment of the stalk; however, this is a variable finding. Even in children, high-dose intravenous urography may be utilized to maximally distend the ureters thus enhancing detection. Fluoroscopy of the ureter during intravenous urography with appropriate spot filming can increase the detection of polyps on intravenous urography and assist in delineating the site of attachment. 14 Ureteral polyps may be quite long, even prolapsing into the bladder. They may change position during intravenous urography, further confirming the diagnosis. Retrograde pyeloureterography may be necessary to pinpoint the site of attachment of the polyp. Retrograde displacement of the polyp during ureterography has been documented in literature? O t h e r considerations in the differential diagnosis of interureteric masses include blood clot, nonopaque calculi, and ureteral tumors. The latter are almost nonexistent in children. In a literature review, we could find no case of ureteral tumors in children and only 6 eases of renal pelvic tumors. This r e v i e w is from 1943.15a~ Blood clots commonly form a east of the ureter and can be remarkably similar in appearance to a ureteral polyp. A repeat examination will show passage or lysis of the clot, and multiple films during a single examination often show passage of the clot down the ureter since it is not attached to the ureteral wall. Calculi are rare in children, seldom over a centimeter in length, and are not filiform or wormlike in appearance. They are nonpliable on fluoroscopy and usually cause some degree of ureteral spasm with ureteral narrowing just distal to the calculus. Ureteral polyps, on the other hand, usually cause ureteral enlargement below and around the body of the polyp. Uric acid ealculi ean easily be differentiated from polyps or clot by non.contrast computer tomography (CT) since uric acid calculi have high attenuation in the range of 75-85 Hounsfield units (HU) whereas polyps have attenuation in the soft tissue range, 30-40 HU. L7.18 In children the differential diagnosis usually is between ureteropelvic junction obstruction and ureteral polyps. One of the clues supporting the diagnosis of fibroepithelial polyps is the faet that tlae renal pelvis funnels well into a dependent ureteropelvic junction in patients with
521
polyps. This is in contrast to patients with classic ureteropelvic junction obstruction. Patients with polyps never have a lucent defect caused by crossing fibrous or vascular bands. 1 The preponderance of male patients is 3 to 1 in the literature.S There also seems to be a preponderance for the left side, and the upper ureter is usually the site of the polyp base.1-~2 Many clinical, radiologic, morphologic, and surgical aspects of fibroepithelial polyps of the ureter have been reported previously, but there are two points that are emphasized in the present ease. First it is important to locate the base of the polyp by r a d i o g r a p h i c means; if identifieation cannot be made by intravenous urography, retrograde and/or antegrade pyelography should be performed. The ureteral polyp on the left side was located proximal to its base and a 4-era ureterostomy w a s necessary to locate and excise it. The morbidity would have been much less had we known the position of its base prior to operation. As far as we know, this is the first instance of a polyp being proximal to its base without retrograde pyelography being performed prior to the operation. It is also the first instanee in which a small polyt~,,caused obstruction by retrograde bu.nching. It is likely that the intermittent obstruction of the left ureter was eaused by retrograde "bunching" of the polyp as it only measured 2 m m in diameter and had a very narrow base. The second observation that requires emphasis in the pediatric eases is a preponderance of instances in which a ureteroureterostomy or ureteropyelostomy is necessary, for removal of the polyp alone would leave an obstructing base. In }he more recent adult literature, excision of the polyp base was all that was necessary. When ,operating on children, one should be prepared to excise the entire segment of the ureter where the insertion of the polyp base is located. This was necessary in our ease on the right side and in eases reported by others. L9-13 The etiology of ureteral polyps is unknown, but because they are present at an early age and seldom show evidence of infection, a developmental defect has been considered, s This is supported b y l ease in which a ureteral polyp was diagnosed in a newborn. 10 Histologically, ureteral polyps are composed of a fibrovaseular core, covered by a thin oneto-two-cell thick urothelium. This is the aPpearance of fibroepithelial polyps of the ureter, I generally encountered in the literature. 5 6,,1 3 In previously examining five other polyps, urothe522
lial hyperplasia was present in two, inflammation of varying degree in four, hemorrhage in all, and ureteritis cystiea in one. Naucler, e t a l . 6 reported a constriction of the polyp base. This eonstrietion is supposed t o identify the polyp base. We were not able to identify this eonstrietion on either side, and i t has not been mentioned in other reports suggesting that the phenomenon of constriction i s not common. The prognosis of ureteral polyps is exeellent and recurrenees have not been reported in s p i t e of observations of up to fifteen years. 4,5 Geisinger Clinic; Danville, Pennsylvania 17822::; (DR. BARTONE) ' References 1. Macksood MJ, Roth DR, Chang CH, and Perlmutter AD: Benign fibroepitheliai polyps as a eause of intermittent u r e t e r o , pelvie junction obstruetion in a child: a ease report and review of the literature, J Urol 134:951 (1985), 2. Williams JI, and Kenawi MM: The prognosis of pelviure* teric obstruetion in childhood: a review of 190 eases, Fur Uro! 57 (1976). 3. Johnston JD, Evans JP, Glassberg K1, and Shapiro SR'. Pelvic hydronephrosis in children: a review of 219 personal cases;: ] Urol 117:97 (1977). 4. Debruyne FMJ, Moonen WA, Daenekindt AA, and Delaere KPJ~ FibroepitheliaI polyp of ureter, Urology 16:355 (1980). 5. Berger RM, Lebowitz JM, and Carroll PA: Ureteral polyp~ presenting as ureteropelvie junetion obstruction in children, J Urol 128:805 (1982). 6. Naucler J, Johansson SL, Nilson AE, and Pettersson S: Fi~ broepithelial polyps of the ureter, Scand J Urol Nephrol 17:379
(1983). 7. Williams PR, Feggetter J, Miller I1A, and Wiekham JEA: The diagnosis and management of benign fibrous ureterie polyps, Br J Urol 52:253 (1980). 8. Banner MP, and Polleek HM: Fibrous ureteral polyps, Ha, diology 130:73 (1979). 9. Eilenberg J, Serry W, and Cole A: Multiple fibroepithelial polyps in the pediatric age group: ease report, J Urot 117:793 (1977). 1O. Schulman CC: Ureterie polyp as a cause of hydronephrosis in ehfldhood, J Pediatr Surg 13:537 (1978). 11. Thorup J, Pedersen PV, and Clausen N: Benign nretera! polyp as a cause of intermittent hydr0nephrosis in a child, J Ur0t 126:796 (1977). 12. Roodhooft AM, Gentens P, and Van Aeker Kj: Benign urea, teral fibrous polyp as a cause of obstruction in children, Pediai!: Rad 15:429 (1985). 13. Musselman P, and Kay It: The spectrum of urinary fi" broepithelial polyps in children, J Urol 136:429 (1985). 14. Hughes FA III, and Davis CS: Multiple benign ureteral fi~ brous polyps, AJR 126:723 (1976), 15. Schlapik D: Papillary carcinoma of the kidney in c h i l d hood, Urol Cutan Rev 47:183 (1943). 16. Koyanagi T, et ah Transitional eelI earcinoma of renai pelvis in an infant, J Urol i i 3 : 1 1 4 (!975). 171 Parienty RA, et ah DiagnOstic value of CT numbers ifi: pelvoca!yeeal filling defects, Radiology 145:743 (1982). 18. Pollack HM, et al Computed tomography of renal pelvi~ filling defect, Radiology 138:645 (1981). 19. Soderdahl DW, and Sehuster SR: Benign ureteral polyp in" the newborn, JAMA 207:1714 (1969).
UROLOGY
/
JUNE 1990
/
VOLUME XXXV, NUMBER 6i~