A two month old term female has an umbilical lesion. There is a history of spotting on her clothing that has resolved with the use of silver nitrate. The abdominal exam is normal except for a small scabbed area in her umbilicus and attempted probing does not reveal a sinus tract. The ultrasound ordered by the pediatrician reveals a 3 to 6 mm hypoechoic tract at the bladder extending to the umbilicus. The best next step in management is

 

 

[size=20px]A repeat abdominal ultrasound in six months

 

B voiding cystourethrogram

 

C repeat silver nitrate treatment

 

D laparoscopic or open excision of the tract alone

 

E laparoscopic or open excision of the tract with a cuff of bladder[/size]

E

Think again my dear

D

Think again my friend

B voiding cystourethrogram

Think again my friend

A

A

correct

 

The allantois (Gr. allanto- means sausage and eidos is shape) helps the embryo exchange gases and handle liquid waste. In placental mammals it is part of the umbilical cord and is an out-pouching of the hindgut. The allantois becomes the urachus that connects the fetal bladder to the yolk sac (removes waste from the fetal bladder). The urachus is eventually obliterated to form the median umbilical ligament. Four developmental problems can occur: urachal cyst (most common), fistula, diverticulum or sinus tract.

 

Most urachal cysts remain clinically silent until being discovered incidentally or, rarely, when they produce symptoms (usually from infection or stone formation). Ultrasound is the diagnostic test of choice, although a fistulogram may be useful if a tract is found. Voiding cystourethrogram is not necessary since the incidence of unsuspected lower urinary tract abnormalities in patients with urachal anomalies is quite small and the test is unlikely to identify a tract. Many children with granulation tissue remnants and other umbilical anomalies are referred to the pediatric surgeon for consultation but few have an underlying urachal or omphalomesenteric abnormality. Ultrasound in these newborns sometimes demonstrates a questionable urachal sinus tract or cyst. In the absence of symptoms in a newborn, a period of observation with a repeat ultrasound is a reasonable approach. There have been a few recent reports advocating observation of even symptomatic urachal abnormalities; however the risk of recurrent infection and future malignant transformation is unknown.