Abnormal appearance of the umbilicus: an indicator of urachal anomalies.

The urachus is an intra-abdominal fibrous remnant of the allantois. The non-involution of the allantois can result in urachal anomalies. The abnormal appearance of the umbilicus may be a sign of such anomalies. We have observed 3 cases of term neonates with atypical appearance of the umbilical stump, all of which manifested urachal anomalies, as documented by ultrasound scan. These appearances are rarely described in the literature, and seem to regress at around 2 months. Therefore, it is important that healthcare professionals should be aware of the possible implications of atypical umbilical stumps, evaluate each case accordingly and, if an urachal anomaly is diagnosed, refer the patient to a paediatric surgery centre, as such malformations carry an underlying risk of infection or malignancy.