Vesico-urachal diverticulum is one of the congenital urachal remnant abnormalities.
It is the proximal equivalent of a urachal umbilical sinus, representing a result of the failure of the urachus to close at the urinary bladder, forming an out-pouching of variable length from the anterosuperior aspect of the urinary bladder, which does not communicate with the umbilicus.
This anomaly is identified as a urine-filled anterosuperior extension from the bladder dome on all imaging modalities.
A urachal diverticulum frequently coexists with congenital obstruction of the lower urinary tract. Rarely a malignancy can arise within the diverticulum: see urachal carcinoma.