Urachal cysts are one of the manifestations of the spectrum of congenital urachal remnant abnormalities.
Urachal cysts usually remain asymptomatic until complicated by infection or bleeding.
Infected urachal cyst can occur at any age.
Urachal cysts form when both the umbilical and vesical ends of the urachal lumen close while an intervening portion remains patent and fluid filled. It can be drain through the umbilicus, bladder, or through the peritoneum and into intraperitoneal organs. Rarely it can cause peritonitis and abdominal symptoms.
The most common pathogens of urachal abscess are Staphylococcus, E. coli, Pseudomonas, and Streptococcus.
An uncomplicated urachal cyst appears as a collection of simple fluid localized in the midline of the anterior abdominal wall, between the umbilicus and the pubis and often contiguous with the bladder dome.
Treatment and prognosis
Treatment consists of IV antibiotic therapy and surgical excision. Drainage is usually associated with a high rate of relapse. Sometimes it is advisable to drain the cyst contents before its excision.
For an infected urachal cyst, bladder adenocarcinoma should be considered. For a non-infected urachal cyst general imaging differential considerations include:
- 1. Berrocal T, López-pereira P, Arjonilla A et-al. Anomalies of the distal ureter, bladder, and urethra in children: embryologic, radiologic, and pathologic features. Radiographics. 22 (5): 1139-64. Radiographics (full text) - Pubmed citation
- 2. Yu JS, Kim KW, Lee HJ et-al. Urachal remnant diseases: spectrum of CT and US findings. Radiographics. 21 (2): 451-61. Radiographics (full text) - Pubmed citation
- 3. C. Pesce: Relevance of infection in children with urachal cysts. European Urology, 2002; 38:457-460
- 4. S. Navarrete, A.S. Ismayel, R.S. Salas, et al: Treatment of Urachal Anomalies: a Minimally Invasive Surgery Technique. JSLS, 2005
- 5. N. Chauvin, J.B. Domachowske: Infected Urachal Cyst Presenting as Fever of Unknown Origin. Clinical Pediatrics, 2005; 44:85-87