Review Articles

Congenital Urethral Anomalies in Boys. Part II

Abdolmohammad Kajbafzadeh*

Department of Pediatric Urology, Children's Hospital Medical Center, Tehran University of Medical

Sciences, Tehran, Iran

ABSTRACT

Introduction: In the second part of this article, congenital urethral anomalies other

than posterior urethral valve were reviewed.

Materials and Methods: The anomalies considered in the current review were

anterior urethral valve, lacuna magna, syringocele, Cobb's collar, duplication of

urethra, megalourethra, and prostatic urethral polyps. The literature was extensively

reviewed concerning the presentations, diagnosis, different types of treatment

modalities, morbidity, mortality, and new concepts for the above disorders.

Result: Anterior urethral valves or diverticula are the most prevalent congenital

anomalies of anterior urethra. The lacuna magna is the largest depression in the

dorsal aspect of the fossa navicularis. It is demonstrable on a well-performed voiding

cystourethrography of the distal urethra. The dilated Cowper's gland duct is the other

missed diagnosed anomaly of the urethra in boys. The congenital narrowing of the

bulbar urethra with a variable clinical presentation and obstruction grade and

different types of anterior urethral obstruction are the most common presentation of

these anomalies. However, other symptoms or signs including, hematuria, bloody

spotting on underwear, discomfort or sever pain in the vicinity of the glance,

interrupted voiding, infection, bulging of anterior urethra, enuresis, and postvoiding

dribbling are the only nonspecific manifestations of these disorders.

Conclusion: All of these disorders are demonstrable on a well-performed voiding

cystourethrography of the distal urethra. The urologist must be aware about these

uncommon congenital anomalies and the anterior urethra should be carefully

evaluated for such anomalies. Diagnosis of these entities is elusive unless the physician

is looking for them. Nonspecific symptoms mentioned here besides radiographic

findings can be a valuable clue for diagnosis.

KEY WORDS: urethral anomalies, valves, obstruction, duplication, syringocele, megalourethra,

polyp, Lacuna Magna, diverticula, boy

125

Urology Journal

UNRC/IUA

Vol. 2, No. 3, 125-131 Summer 2005

Printed in IRAN

Anterior Urethral Obstruction

Anterior urethral valve (AUV) is a rare cause of

congenital urethral obstruction in boys. AUV is

associated mainly with a proximal diverticulum

(Figure 1).(1) It may be found anywhere distal to

the membranous urethra, usually proximal to the

penoscrotal junction.(2) Depending on the age of

the patient and the severity of obstruction,

clinical presentation highly varies from a stream

that dribbles and voids poorly to

hydroureteronephrosis and end-stage renal

disease. 

The most common cause of congenital urethral

*Corresponding author: No 36, 2nd Floor, 7th St,

Aaadat-abad Ave, Tehran 19987, Iran.

Tel: ++98 21 2208 9946, Fax: ++98 21 2206 9451

E-mail: kajbafzd@sina.tums.ac.ir



Congenital Urethral Anomalies in Boys

obstruction is posterior urethral valve (PUV), and

AUV is reported to be 7 times less common;

however, it can be equally as devastating.(1) The

embryological pathophysiology of AUV remains

uncertain. Various proposed etiologies exist,

including an abortive attempt at urethral

duplication, failure of alignment between the

proximal and distal urethra, incomplete

formation of the ventral corpus spongiosum,

congenital cystic dilation of the periurethral

gland, and a ruptured Cowper's duct cyst.(3) AUV

may locate in every portion of the anterior

urethra with almost equal incidence.(4) It may

even be found in fossa navicularis.(5) It is likely

that a pathophysiologic spectrum exists from

valve to diverticulum formation associated with

the degree of urethral dilation.(1) Intrauterine

urethral obstruction can result in severe bladder

dysfunction after birth, which does not

necessarily resolve after valve resection. If severe

neonatal obstruction exists, urinary diversion by

vesicostomy, and antibiotics, electrolyte

management, and assessment of renal function

improvement are recommended.(6,7) The abnormal

bladder function can occasionally be so severe as

to end with augmentation cystoplasty.

An anterior urethral diverticulum should be

considered in every case of anterior urethral

obstruction. Urethral obstruction usually can be

detected by antenatal scanning. When anterior

urethral obstruction is suspected, an antegrade

cystourethrogram is the investigation method of

choice as any attempt at urethral catheterization

may disrupt the pathology, and the exact

diagnosis can be missed. Urodynamic studies

through a suprapubic catheter before and after

valve ablation can be a helpful baseline

investigation.(8) If secondary pathological changes

such as bladder dysfunction and upper tract

dilation do not improve after valve resection,

other treatment options should be considered.

The rapid improvement in bladder function and

upper tract dilatation in these cases must be good

prognostic factors. We recommend that

urodynamic studies be performed in all patients

with urethral obstruction before and after

treatment to help predict the future prognosis.

The association of AUV with PUV is extremely

rare in the literature. In 1982, Graham and

colleagues(2) have reported an association of an

anterior urethral diverticulum with PUV in a

newborn. Patients may present with poor urinary

stream, recurrent urinary tract infections, or

kidney failure. Depending on the severity of

anatomic obstruction, patients may present early

at birth or later in childhood if obstruction is

minimal.(1)

An AUV in almost all cases is actually a

congenital urethral diverticulum.(9) During

voiding, the diverticulum expands, ballooning

ventrally and distally beneath the thinned corpus

spongiosum. The flaplike dorsal margin of the

diverticulum then extends into the urethral

lumen, occluding urinary flow (an obstructing

valve). Anterior urethral valves have been

described in every portion of the anterior urethra

with almost equal incidence. They may be small,

minimally obstructive, and of limited clinical

concern. Often, though, they are severely

obstructing and result in all the findings seen

with PUVs. 

Diagnosis of AUVs is confirmed on voiding

cystourethrography. At times, difficulty with

catheterization may be encountered because the

catheter preferentially slips into the diverticulum.

126

FIG. 1. Typical radiologic appearance of anterior urethral

valves



Kajbafzadeh

However, this occurs less often than one might

expect, because the proximal wall of the

diverticulum is often not hollowed out nearly as

extensively as the distal wall. Because the

diverticula almost always are placed ventrally in

the midline, a dorsally oriented coudé-tipped

catheter usually can be negotiated with less

difficulty into the more proximal urethra. To

establish the diagnosis, the entire penile urethra

must be included in the voiding phase of the

cystourethrography, or more distally located

lesions will be missed. 

The etiology of these anomalies is not entirely

clear, but they seem to represent incomplete

fusion of a segment of the urethral plate. Another

possible cause might be a focally incomplete

development of the corpus spongiosum with

ballooning of the urethral mucosa due to

inadequate support. Small, nonobstructing

diverticula often appear stable for many years

and do not show continuous enlargement and

progressively worsening obstruction. 

Initial management of a congenital AUV is the

same as that for the more commonly seen PUV.

Initial imaging studies assess the extent of

hydronephrosis, the thickness and quality of the

renal parenchyma (echogenicity on renal

ultrasonography and uptake on renal scan), and

the presence or absence of vesicoureteral reflux.

Infants presenting with urosepsis and/or severe

renal insufficiency require a period of

transurethral or suprapubic (by percutaneous

route) catheter drainage for stabilization,

antibiotics, electrolyte management, and

assessment of renal functional improvement. As

with infants with PUVs, a temporizing tubeless

diversion (vesicostomy, loop ureterostomy) may

be chosen on an individual basis.(6)

Management of the urethral anomaly may be

endoscopic or open. A hooked, single-wire,

electrocautery knife can be used to engage the

distal margin of the diverticulum and incise it in

the midline. When performing this procedure,

the surgeon must be very careful not to place the

tip of the wire too close to the floor of the

diverticulum. At this location, the wall of the

urethra can be very thin, and thermal injury may

result in development of a urethrocutaneous

fistula. Even after satisfactory destruction of the

leaflet, postoperative urethrography is often

disappointing, because the appearance of the

diverticulum may be unchanged. One must

carefully assess the quality of flow (flow rate if

the child is old enough) and the extent of filling

of the urethra distal to the anomaly, to evaluate

the results of the procedure. 

Some surgeons have advocated open resection

and reconstruction of the diverticulum.(9) This

technique allows one to completely excise the

distal lip and provide a more homogeneous

caliber to the urethra. In most cases, a patch

graft urethroplasty is the preferred procedure. If

the diverticulum is on the penile shaft, a sleeve

dissection of the penile shaft skin from the

corona to the penoscrotal angle allows the

urethroplasty to be completed without

overlapping suture lines. 

Some AUVs may not be associated with a

urethral diverticulum. De Castro and

colleagues(10) have described 3 children with

anterior urethral membranes without the

associated diverticulum. 

Lacuna Magna or Sinus of Guerin

Formation of the distal glanular urethra may

occur by a combination of 2 separate processes:

proximal fusion of the urethral folds and distal

ingrowth of ectodermal cells. It is generally

thought that the stratified squamous lining of the

fossa navicularis results from an ingrowth of

surface ectoderm as far proximally as the valve of

Guerin. The lacuna magna (also known as the

sinus of Guerin), which can produce symptoms of

hematuria and dysuria in some boys, may form

as a result of dorsal extension of this ectodermal

ingrowth. It has been suggested that the entire

penile urethra might differentiate from fusion of

the urethral plate via the mechanism of epithelial-

mesenchymal interactions.(11,12) The lacuna

magna is the largest depression in the fossa

navicularis. Guerin(13) has described the valve of

Guerin as a septum between the lacuna magna

and the urethral lumen, which may act as a valve

(Figure 2). The anomaly has been described in

the urologic literature since 1980, at which time

Somner and Stephens(14) first drew attention to

the fact that it may present with specific

symptoms and/or dysuria, hematuria, blood in

urethra, and spotting of underclothes.(14-18)

Although it may be present in 30% of boys as a

small pit or sinus,(17) only a few become

symptomatic owing to the valvelike effect of the

septum. If the inferior wall of the sinus balloons

during micturition, it may elongate and trap

urine in the lacuna magna. Chronic distension

and irritation of the diverticulum probably are

127



Congenital Urethral Anomalies in Boys

responsible for the dysuria and hematuria.(14-16)

Micturating cystourethrography must be

performed meticulously if this lesion is not to be

missed, and the entire distal urethra must be

included on the radiographic films (Figure 2).

Contrast medium on towels or clothing may

obscure or simulate the valve of Guerin.

Similarly, retrograde studies, particularly those

that employ the Zipser clamp, may be less

accurate, because the lacuna is compressed or a

catheter may be placed beyond its orifice.(19)

Another fallacy is to misinterpret the

diverticulum as contrast medium within the

prepuce or on the skin. One must remember to

keep the end of the urethra always in sight. 

Syringocele

The dilated Cowper's gland duct is referred to

as a syringocele (in Greek, syringe means "tube"

and cele means "swelling"). These anomalies seem

to be more common than previously reported.

Syringoceles are cystic dilations of Cowper's

gland duct within the bulbous urethra.(20) They

are usually small, inconsequential lesions. But

rarely, they can be of sufficient size to cause

varying degrees of outlet obstruction. 

Lesions of Cowper's gland duct have various

appearances. A system to classify each of these

appearances is offered to diagnose these lesions

more precisely. The urethrographic and

endoscopic characteristics of dilated Cowper's

gland ducts are classified in 4 groups:

1. Simple syringocele, a minimally dilated duct

2. Perforate syringocele, a bulbous duct that

drains into the urethra via a patulous ostium

and appears as a diverticulum

3. Imperforate syringocele, a bulbous duct that

resembles a submucosal cyst and appears as a

radiolucent mass

4. Ruptured syringocele, the fragile membrane

that remains in the urethra after a dilated

duct rupture(20)

Cystic dilatation of Cowper's gland ducts

(Cowper's syringocele) is uncommon in children

and is frequently asymptomatic; however, it may

cause urinary infection, hematuria, dysuria, and

obstructive voiding symptoms. Only a quarter of

children with obstructive syringocele need

surgical intervention. The true clinical

significance of Cowper's syringocele lies in its

potential to cause urethral obstruction. Careful

clinical, radiologic, endoscopic, and urodynamic

evaluation is necessary to avoid unnecessary

surgery.(21)

Management, where necessary, is usually by

endoscopic unroofing. After unroofing, a

diverticulumlike defect may result on the

posterolateral wall of the bulbous urethra.

However, these defects are rarely obstructing and

do not need further management.

Marsupialization of the syringoceles can cure

urinary infection and hematuria, but voiding

symptoms may persist. 

Cobb's Collar 

The Cobb's collar or Moormann's ring is a

congenital narrowing of the bulbar urethra with

variable clinical presentation and obstruction

grade. Tubular or cystic dilatation of Cowper's

gland duct has been called a syringocele, while

congenital urethral narrowing is known as Cobb's

collar.

It is important to distinguish congenital

urethral obstruction, Cobb's collar, from type-III

PUV as described by Young.(22) Congenital

urethral obstruction, Cobb's collar, should be

differentiated from a congenital obstructive

posterior urethral membrane. Congenital

obstructive posterior urethral membrane may be

a variation of a type-I urethral valve, supporting

the theory of unified morphology in boys with

congenital obstruction of the posterior urethra.

In some congenital obstructive posterior urethral

membrane cases, the membrane may prolapse as

far as the bulbar urethra. However, the leaflet is

supported by attachments to the verumontanum

in congenital obstructive posterior urethral

membrane, but not in Cobb's collar.

Meticulous cystourethroscopy is indispensable

for detecting a clinically significant bulbar

narrowing. Transurethral incision of the lesion is

useful as a primary treatment in the majority of

128

FIG. 2. The lacuna magna  (sinus of Guerin)



Kajbafzadeh

cases, even with concurrent vesicoureteral reflux

and unstable bladder. A cold knife is preferable to

electrocautery for incising this fine anterior

urethral lesion.(23)

It appears that syringoceles are often

associated with a Cobb's collar, in keeping with

the possible origin of both structures from the

region of the urogenital membrane. Narrowing in

the bulbar urethra may, however, be an incidental

finding in many of the cases.(24)

The more proximal lesion is a membranous

obstruction that is able to prolapse as far as the

bulbar urethra, but has paramedian folds that

attach along the posterior wall of the urethra to

the verumontanum and is due to persistence of

an embryologic attachment between the distal

verumontanum and the anterior wall of the

posterior urethra. The more-distal narrowing is

not always obstructive and is primarily a bulbar

urethral membrane; it is independent of the

verumontanum and external sphincter and may

represent a persistence of part of the urogenital

membrane. There are 2 distinct types of

congenital obstruction of the proximal urethra,

with an association to the verumontanum being

the distinguishing feature.(25) Cobb's collar or

Moormann's ring is a stricture of the bulbar

urethra that is largely unrecognized but has

considerable relevance urologically as the site of

congenital or postinstrumental strictures.(26)

Duplication of Urethra

Accessory urethra or duplication of the urethra

is a rare anomaly. The vast majority occurs in the

sagittal plane; however, collateral or side-by-side

duplications in the absence of bladder duplication

also exist. 

Urethral duplications are divided into sagittal

and collateral types.(27,28) Those not associated

with bladder duplications occur almost exclusively

in males. They are often accompanied by other

anomalies such as anorectal anomalies or

duplication of the penis.(28,29) Urethral duplication

in females is almost always associated with

bladder duplication (Figure 3). 

The etiology of urethral duplication is not

clear.(27) It is probably due to misalignment of

some sort between the termination of the cloacal

membrane and its relationship with the

formation of the genital tubercle and urogenital

sinus.(28) The following classification has been

accepted in the literature: 

Type I, incomplete duplication; 

Type II, complete duplication, IIa. two meatuses,

noncommunicating urethras arising

independently from the bladder; IIb, a second

channel arising from the first and exiting

independently, complete duplication joining at

one meatus; 

Type III, duplication as a component of caudal

duplication. 

This classification may apply to either dorsal or

ventral duplications. The perineal or rectal type

associated with a stenotic, normally located

penile urethra, is placed in the IIa category. The

Y-type fistula usually takes its origin from the

prostatic urethra and is commonly associated

with stenosis of the anterior portion of the

normally situated urethra.(28) Children with

complete and incomplete forms of accessory

urethras usually present with 2 urinary streams.

Infection in the partially stenotic orifice is

sometimes the presenting symptom.(28)

A proper clinical examination (under

anesthesia, if needed), a micturating

cystourethrography, an ascending urethrography,

and a urethrocystoscopy will give a complete

picture of the altered anatomy. Based on the

findings with reference to adequacy of channels,

abnormality of location, and symptoms,

individually tailored treatment is advised. Most

often, the ventral urethra is functionally better

and can be utilized by plastic procedures, as

necessary. The dorsal urethra becomes

obliterated either spontaneously or by ablative

intervention.

129

FIG. 3. A typical urethral duplication with a hypospadias

type



Congenital Urethral Anomalies in Boys

Many asymptomatic children can be left

untreated. Cosmetic correction of the division of

the septum and creating an apparently single

terminal orifice may be necessary when the

orifices are close to each other at the tip of the

glans. In some cases an end-to-side

urethrourethrostomy may be done.(30)

Megalourethra

Congenital megalourethra is a rare disorder

characterized by the congenital absence of the

corpus spongiosum and/or corpus cavernosum,

leading to dilatation of the urethra.

Megalourethra was described originally by

Nesbitt(31) as a rare congenital abnormality

characterized by dilation of the penile urethra.

This defect has been classified as a scaphoid or

fusiform deformity. In the scaphoid variety, the

corpus spongiosum is thought to be the only

abnormal segment, whereas the fusiform variety

is also associated with defects of the corpora

cavernosa. However, this distinction is arbitrary

and is not based on any recognized embryologic

difference between the two varieties.(29)

Megalourethra is especially common in

association with the prune-belly syndrome and

may represent a defect in development of the

mesoderm, one of the proposed causes for the

prune-belly anomaly.(32)

Prostatic Urethral Polyps

Congenital posterior urethral polyps are rare,

benign lesions that can cause a variety of

symptoms in young boys; the diagnosis is usually

made by cystourethrography and ultrasonography

where the polyp appears as a soft tissue mass

arising at the base of the urinary bladder. 

Hunter is credited with the first documented

case of urethral polyp, and Thompson reported

the first case in a human.(33)

Urethral polyps are rare and anterior urethral

polyps are even rarer. They are usually of

congenital origin. Urethral polyps in children

occur exclusively in boys; the average age is 5.2

years. Mostly, they arise in the posterior urethra,

usually proximal to the membranous urethra.

But, anterior urethral polyps are still very

rare.(34) They are usually single and rarely

multiple.

Urethral polyps have been speculated to

represent a developmental error in the

invagination process of the submucous glandular

material of the inner zone of the prostate.(35)

They are benign lesions (not to be confused with

the polypoid masses of a sarcoma botryoides),

and transurethral excision of the polyps is

curative.(36)

Presentation of urethral polyps is varied

consisting of dysuria,(37,38) retention,(37)

secondary enuresis,(39) and hematuria.(33) They

may present with obstructive symptoms.(40)

Occasionally, they present in adults with

hematuria.(33) Williams(41) has reported

associated vesicoureteral reflux.

Diagnosis of anterior urethral polyps is by

voiding cystourethrography and

cystourethroscopy.(41) However, the penile and

bulbar urethra should be palpated in patients

presenting with retention or dysuria. Indurated

area or lump in the absence of radio-opaque stone

on radiography is suggestive of stricture or rarely

a polyp.

The main symptom is bladder outlet

obstruction, either intermittent or acute. Color

Doppler ultrasonography may be diagnostic by

revealing the polyp's vascular stalk arising from

the posterior urethra.(42) Transurethral resection

of the polyp is the treatment of choice.(36)

However, when this is complicated by the

displacement of the polyp into the bladder,

transvesical removal could be an acceptable

alternative.(36-43) Histologically, these lesions are

benign and there have been no reported

recurrences when they have been removed

completely. The histologic examination reveals a

fibroepithelial core with transitional epithelium

with squamous metaplasia at times. 

References

1. Firlit RS, Firlit CF, King LR. Obstructing anterior

urethral valves in children. J Urol. 1978;119:819-21.

2. Graham SD Jr, Krueger RP, Glenn JF. Anterior urethral

diverticulum associated with posterior urethral valves. J

Urol. 1982;128:376-8.

3. McLellan DL, Gaston MV, Diamond DA, et al. Anterior

urethral valves and diverticula in children: a result of

ruptured Cowper's duct cyst? BJU Int. 2004;94:375-8.

4. Karnak I, Senocak ME, Gogus S, Buyukpamukcu N,

Hicsonmez A. Testicular enlargement in patients with 11-

hydroxylase deficiency. J Pediatr Surg. 1997;32:756-8.

5. Scherz HC, Kaplan GW, Packer MG. Anterior urethral

valves in the fossa navicularis in children. J Urol.

1987;138:1211-3.

6. Rushton HG, Parrott TS, Woodard JR, Walther M. The

role of vesicostomy in the management of anterior

urethral valves in neonates and infants. J Urol.

130



Kajbafzadeh

1987;138:107-9.

7. Van Savage JG, Khoury AE, McLorie GA, Bagli DJ. An

algorithm for the management of anterior urethral

valves. J Urol. 1997;158(3 Pt 2):1030-2. 

8. Kajbafzadeh AM, Janguk P, Ahmady Yazdi C. Anterior

urethral valve associated with posterior urethral valves.

J Pediatr Urol. 2005; 1:433-5.

9. Tank ES. Anterior urethral valves resulting from

congenital urethral diverticula. Urology. 1987;30:467-9. 

10. De Castro R, Battaglino F, Casolari E, Di Lorenzo FP,

Messina P, Pavanello P. [Valves of the anterior urethra

without diverticulum. Description of 3 cases]. Pediatr

Med Chir. 1987;9:211-5.

11. Kurzrock EA, Baskin LS, Cunha GR. Ontogeny of the

male urethra: theory of endodermal differentiation.

Differentiation. 1999;64:115-22.

12. Kurzrock EA, Baskin LS, Li Y, Cunha GR. Epithelial-

mesenchymal interactions in development of the mouse

fetal genital tubercle. Cells Tissues Organs.

1999;164:125-30.

13. Guerin A. Elements de chirurgie operatoire. 3rd ed.

Paris: Chamerot ; 1864. p.587.

14. Sommer JT, Stephens FD. Dorsal urethral diverticulum

of the fossa navicularis: symptoms, diagnosis and

treatment. J Urol. 1980;124:94-7.

15. Seskin FE, Glassberg KI. Lacuna magna in 6 boys with

post-void bleeding and dysuria: alternative approach to

treatment. J Urol. 1994;152:980-2.

16. Bellinger MF, Purohit GS, Duckett JW, Cromie WJ.

Lacuna magna: a hidden cause of dysuria and bloody

spotting in boys. J Pediatr Surg. 1983;18:163-6.

17. Friedman RM, King LR. Valve of Guerin as a cause of

dysuria and hematuria in young boys: presentation and

difficulties in diagnosis. J Urol. 1993;150:159-61.

18. Glenister TW. The origin and fate of the urethral plate

in man. J Anat. 1954;88:413-25.

19. Duszlak EJ Jr, Bellinger MF, Boal DK, Stanford A.

Dorsal diverticulum of the distal male urethra. AJR Am

J Roentgenol. 1982;138:931-3. 

20. Maizels M, Stephens FD, King LR, Firlit CF. Cowper's

syringocele: a classification of dilatations of Cowper's

gland duct based upon clinical characteristics of 8 boys.

J Urol. 1983;129:111-4.

21. Campobasso P, Schieven E, Fernandes EC. Cowper's

syringocele: an analysis of 15 consecutive cases. Arch

Dis Child. 1996;75:71-3.

22. Young HH, Frontz WA, Baldwin JC. Congenital

obstruction of the posterior urethra. J Urol.

1919;3:289-365.

23. Nonomura K, Kanno T, Kakizaki H, Koyama T,

Yamashita T, Koyanagi T. Impact of congenital

narrowing of the bulbar urethra (Cobb's collar) and its

transurethral incision in children. Eur Urol. 1999;36:144-

8; discussion 149.

24. Dewan PA. A study of the relationship between

syringoceles and Cobb's collar. Eur Urol. 1996;30:119-24.

25. Dewan PA, Keenan RJ, Morris LL, Le Quesne GW.

Congenital urethral obstruction: Cobb's collar or

prolapsed congenital obstructive posterior urethral

membrane (COPUM). Br J Urol. 1994;73:91-5.

26. Cranston D, Davies AH, Smith JC. Cobb's collar--a

forgotten entity. Br J Urol. 1990;66:294-6.

27. Ciftci AO, Senocak ME, Buyukpamukcu N, Hicsonmez A.

Complete duplication of the bladder and urethra: a case

report and review of the literature. J Pediatr Surg.

1995;30:1605-6. 

28. Dajani AM, el-Muhtasseb H, Kamal MF. Complete

duplication of the bladder and urethra. J Urol.

1992;147:1079-80. 

29. Appel RA, Kaplan GW, Brock WA, Streit D.

Megalourethra. J Urol. 1986;135:747-51.

30. Middleton AW Jr, Melzer RB. Duplicated urethra: an

anomaly best repaired. Urology. 1992;39:538-42. 

31. Nesbitt TE. Congenital megalourethra. J Urol.

1955;73:839-42.

32. Mortensen PH, Johnson HW, Coleman GU, Lirenman

DS, Taylor G, McLoughlin MG. Megalourethra. J Urol.

1985;134:358-61.

33. Downs RA. Congenital polyps of the prostatic urethra. A

review of the literature and report of two cases. Br J

Urol. 1970;42:76-85.

34. Coleburn NH, Hensle TW. Anterior urethral polyp

associated with hematuria in six-year-old child. Urology.

1991;38:143-4.  

35. Walsh IK, Keane PF, Herron B. Benign urethral polyps.

Br J Urol. 1993;72:937-8.

36. Gleason PE, Kramer SA. Genitourinary polyps in

children. Urology. 1994;44:106-9.

37. Anandan N, Shetty SD, Patil KP, Ibrahim AI. Acute

urinary retention caused by anterior urethral polyp. Br

J Urol. 1992;69:321-2.    

38. Azmy AF. Anterior urethral polyp in a child. Br J Urol.

1990;66:323.  

39. Redman JF. Anterior urethral polyp in a boy. J Urol.

1982;128:1316.  

40. Miroglu C, Ilhan A, Ozdiler E. Congenital urethral polyp

in an adult. Br J Urol. 1988;61:531-2.   

41. Bagley FH, Davidson AI. Congenital urethral polyp in a

child. Br J Urol. 1976;48:278. 

42. Spyropoulos C, Konidaris D, Papanicolaou A,

Stephanidis A, Michael V, Androulakakis PA. Posterior

urethral polyp in a boy, diagnosed by colour Doppler

ultrasonography. BJU Int. 1999;84:881-2.  

43. Foster RS, Garrett RA. Congenital posterior urethral

polyps. J Urol. 1986;136:670-2.

131