[Urachal remnant and acute abdomen: when it's not what it seems]

Among the causes of acute surgical abdomen, infection of a urachal remnant may go unnoticed despite routine complementary studies. We present three cases in boys aged 11, 6, and 4 years who were brought to the emergency department for right iliac fossa pain, fever, and urinary symptoms. Examination and complementary tests results were compatible with acute complicated appendicitis and were sent to surgery. While in the operating room, appendicitis was excluded and inflammatory changes suggestive of infection of the urachal remnant were documented. Complications of urachal remnants should be considered in the differential diagnosis of acute surgical abdomen, since advanced infection of the urachus may be a cause of confusion. A more accurate presumptive diagnosis can change the therapeutic/surgical approach and follow-up.