Symptoms of Urachal Cysts
Urachal cysts are typically asymptomatic until infection occurs, at which point patients present with lower abdominal pain (particularly suprapubic), fever, abdominal mass, and sometimes dysuria or umbilical discharge. 1, 2, 3
Clinical Presentation
Asymptomatic Phase
- Most urachal cysts remain clinically silent and are discovered incidentally, as they occur in approximately 1 out of 5,000 live births but are only clinically relevant in 1 out of 150,000 of the population 4
- The urachus is a fibrous cord extending from the anterior bladder wall to the umbilicus, representing an embryological remnant that normally obliterates to become the median umbilical ligament 1, 4
Symptomatic Presentation (When Infected)
When infection develops, the symptom complex becomes acute and mimics other acute abdominal conditions:
- Lower abdominal pain (particularly suprapubic region, may radiate to the right iliac fossa) - the most common presenting symptom 1, 2, 3
- Fever - indicating active infection 1, 3
- Palpable abdominal mass - representing the enlarged, infected cyst 1, 2
- Dysuria - due to proximity to the bladder 1
Age-Specific Presentations
- Pediatric patients: May present with severe intermittent lower abdominal pain and umbilical discharge 3, 4
- Adult patients: More commonly present with hematuria in addition to abdominal symptoms 4
Important Clinical Pitfalls
The symptoms are nonspecific and frequently misdiagnosed as acute appendicitis or other acute abdominal conditions, leading to delayed diagnosis. 2, 3 This diagnostic delay is particularly dangerous because infected urachal cysts can lead to life-threatening complications including:
- Sepsis 2, 5
- Fistula formation 2
- Rupture leading to peritonitis 2, 5
- Enterocutaneous fistula formation (as a complication of treatment) 1
Diagnostic Approach
When an infected urachal cyst is suspected based on symptoms, imaging should be obtained immediately rather than attempting medical palliation alone, as rupture can occur during conservative management. 5
- Ultrasound is highly sensitive and nonradioactive, making it ideal for initial evaluation, though infected cysts display increased echogenicity that may complicate diagnosis 3, 4
- CT imaging is the typical diagnostic tool showing thick-walled cystic or mixed attenuation lesions 3, 4
- MRI can also be used for diagnosis 1
- Cystoscopy may be employed to evaluate bladder involvement 1
Clinical Context
The condition should be included in the differential diagnosis for patients presenting with atypical lower abdominal pain, particularly when imaging suggests a complicated inflammatory mass in the lower abdomen 2. The diagnosis is critical to make promptly, as bacterial persistence from infected urachal cysts can lead to recurrent infections 6.