UCHs arise due to a failure of closure of the abdominal wall. This occurs following return of the physiologically eviscerated abdominal contents to the umbilical coelom during the fetal period. It is commonly misdiagnosed as a small omphalocele which differentiates itself by having a normal cord insertion, adequate muscle development of the abdominal wall and a wall defect less than 5cm. Omphaloceles also present with healthy skin surrounding the base of the cord. We present a table with the main differential diagnoses of UCH comparing embryological origin, clinical features, associated anomalies and prognosis. (Table-1)

The management of UCH begins at the point of delivery, as inadequate clamping of the umbilical cord may cause damage to its contents. UCH represents a defect at a more advanced stage of embryological development than the other aforementioned abnormalities’. UCH has a lower morbidity overall, as it is not associated with other anomalies, has fewer complications and is relatively straightforward to resolve with an excellent prognosis. Furthermore, the surgical procedure to manage a UCH carries a lower morbidity in comparison to that for gastroschisis and omphalocele.

As mentioned previously, the urachus is an embryologic remnant derived from the lack of obliteration of the allantois lumen. It carries arteries on either side, which undergo fibrosis forming the medial umbilical ligaments. The most frequently observed urachal malformations are the persistence of a urachus and urachal cyst. Due to their anatomical location they are sometimes misdiagnosed as omphalitis, granulomas secondary to scarring of the umbilicus or infection of the umbilical vessels. The prenatal diagnosis of patent urachus is made by ultrasound or magnetic resonance, showing a cystic mass at the base of the umbilical cord communicating with the bladder, being easily mistaken for an omphalocele or gastroschisis4. Suspicion of a patent urachus begins with the physical exam by observing an abnormal umbilicus that is permanently wet. The clinical diagnosis is confirmed with US where a connection between the bladder dome and the umbilicus is visualized. Furthermore, a urethrocystogram can be performed, introducing contrasted liquid through the umbilicus which in UCH shows a conduit that leads to the bladder [2].

The urachal remnants in patients less than six months old normally resolve spontaneously, being supported with urethral catheterization to facilitate their closure. If it fails to resolve spontaneously, surgical resolution is recommended via laparoscopy or open surgery through an umbilical incision. The primary goal for a satisfactory management is to prevent urinary tract infections and, to a lesser extent, avoid neoplastic urachal changes. The risk of malignancy of the umbilical remnant is rare and uncertain [10]. Some authors suggest that the absence of epithelial elements would make it unlikely to undergo malignant degeneration; therefore waiting for spontaneous resolution is a reasonable alternative [11]. Similar to a UCH, a patent urachus shows little association with other malformations and its early, accurate diagnosis is crucial to avoid further complications.

There are few case reports of umbilical cord cysts described in the literature [7,11,12,13], and as mentioned previously it is one of the main differential diagnosis of UCH and commonly related with persistent urachus. The case described has evisceration of abdominal contents into the cord, not considered as a cyst, but still a cord anomaly which derives from the same embryologic origin. Therefore, we think it is important to rule out the presence of urinary anomaly when a pathologic swelling of the cord is found.

Due to the low incidence of both UCHs and a patent urachus as well as its broad range of differential diagnoses, it is important to know their clinical presentation and the diagnostic perinatal methods employed for appropriate management and favorable results. This relies on knowing when to suspect possible associated anomalies and when complementary studies might be needed, as in the case of a gastroschisis or omphalocele. Furthermore, it is important to note that trivial umbilical pathologies may be misdiagnosed as UCHs and other abdominal defects indicating surgery. It is also important to be aware that despite being a rare occurrence, there is the rather interesting possibility of a UCH and a patent urachus existing simultaneously.