Anal atresia associated with cutaneous melanocytic naevi and single umbilical artery: A rare neonatal case report

Anorectal malformations are a heterogeneous group of congenital anomalies frequently associated with defects involving other organ systems. Single umbilical artery is a common umbilical cord abnormality and is recognized as an important antenatal marker for congenital anomalies, including gastrointestinal malformations. Congenital melanocytic naevi are usually isolated dermatological findings; however, their association with structural congenital anomalies is uncommon and may suggest shared embryological mechanisms. We report a rare neonatal case of anal atresia associated with multiple cutaneous melanocytic naevi and antenatally detected single umbilical artery. A female neonate was born at term to a 27-year-old mother by lower-segment cesarean section. Antenatal ultrasonography detected a single umbilical artery and poor visualization of the perianal muscular complex, raising suspicion of anorectal malformation. Postnatal examination confirmed anal atresia, along with multiple melanocytic naevi distributed over the trunk, face, and extremities, and an associated umbilical hernia. The neonate was managed in the neonatal intensive care unit and evaluated by a multidisciplinary team, with a staged surgical approach planned. This case emphasizes the diagnostic value of antenatal markers such as single umbilical artery, the need for comprehensive evaluation in anorectal malformations, and the importance of reporting rare associations to enhance understanding of congenital anomaly patterns.