Case report: the antenatal ultrasound diagnosis of megalourethra

Congenital megalourethra: outcome after prenatal diagnosis in a series of 4 cases

OBJECTIVE

The purpose of this series is to describe the prenatal sonographic findings and pregnancy outcome in 4 cases of congenital megalourethra.

METHODS

Three cases of fusiform-type megalourethra and 1 case of scaphoid-type megalourethtra were diagnosed prenatally by sonography between 20 and 24 weeks' gestation. The key findings for diagnosis included sonographic features of lower urinary tract obstruction in association with dilatation and elongation of the penile urethra in all 4 cases. Severe oligohydramnios was detected at the time of diagnosis in only 1 case. Prenatal chromosome analysis was available in 3 cases and revealed a normal 46,XY karyotype. Information on pregnancy outcome was available in all cases.

RESULTS

The parents opted for elective termination of pregnancy in 1 case when decreased amniotic fluid volume and echogenic kidneys were documented at the follow-up scan. Among the 3 ongoing pregnancies, there were 2 premature cesarean deliveries at 28 and 31 weeks and 1 vaginal delivery at term. All neonates had severe lung hypoplasia and died in the early neonatal period.

CONCLUSIONS

Congenital megalourethra is associated with poor perinatal outcome. Because this condition can be diagnosed prenatally in the context of lower urinary tract obstruction, detailed examination of the external genitalia in these cases should be mandatory.

Megalourethra and urethral diverticula

Megalourethra and urethral diverticula encompass a diverse group of congenital and acquired urethral defects. The appropriate management of these anomalies relies on a keen appreciation of phallic anatomy and an understanding of urethral embryology. A thorough history and physical examination--including a careful evaluation of the urinary tract--is necessary to identify associated congenital anomalies. Finally, satisfactory surgical management demands meticulous attention to surgical technique.

First-trimester sonographic diagnosis of distal urethral atresia with megalourethra in VACTERL association

Congenital megalourethra is a rare disorder. We present an early case diagnosed in the first trimester. Prenatal ultrasound showed a megalourethra with a normal fetal bladder, hyperechogenic cystic right kidney and single umbilical artery. After termination of pregnancy, necropsy confirmed all sonographic findings and revealed other malformations (spina bifida occulta, anal atresia, tracheo-oesophageal fistula, brachydactylia) resulting in the diagnosis of VACTERL association. The prenatal diagnostician should seek histological examination firstly to confirm his findings and secondly to avoid missing associations and inherited malformations.

Prenatal diagnosis and management of abnormalities in the urologic system

We have reviewed the prenatal diagnosis and management of abnormalities in the urologic system. Urologic anomalies may be caused by embryologic aberrations, genetic disease, or a nonrandom association with other structural abnormalities. There is a wide range of prognoses, depending on the cause and the impact of the anomaly on the production of amniotic fluid. Management focuses on obtaining an accurate prenatal diagnosis, providing appropriate counseling, and ensuring the proper surveillance or treatment before and after birth.

Congenital megalourethra: a case report

We describe a case of a male infant with a scaphoid megalourethra. A physical examination showed a large, flabby phallus with bilateral undescended testes. The corpus spongiosum was absent with normal corpora cavernosa. Urethrography showed a crescent-shaped dilatation of the anterior urethra. Further examination revealed an association with concomitant urogenital anomalies, right renal hypoplasia-dysplasia, bilateral vesicoureteral reflux and the prune-belly syndrome. A urethroplasty with resection of the excess urethral tissue and reconstruction of the urethra was performed. There was a satisfactory surgical result and the patient now voids without difficulty.

Congenital megalourethra

Megalourethra, a rare congenital disorder involving the anterior urethra, is subdivided into two types: Fusiform and scaphoid. Two cases of scaphoid type megalourethra are reported. The first patient, a 5-weeks-old infant diagnosed at birth as having the prune belly syndrome was admitted to the hospital with vomiting and failure to thrive. Intravenous pyelogram revealed marked dilatation of the left ureter and a bladder diverticulum. A penile urethrostomy was performed. The second patient, born to healthy parents after an uneventful pregnancy and delivery, was found to have an enlarged and deformed penis. The baby voided with a poor stream and a concomitant swelling of the penis was noted. Retrograde uretrography showed a sac-like dilatation of the penile urethra. Surgical revision was carried out a 2 stage procedure and was completed (Nesbitt's operation) after 4 months. The patient did well postoperatively and voided with a normal stream without any abnormality of the penile shaft.