Vanishing enteric duplication cyst presenting with melaena

A toddler presented with melaena on a background of a possible enteric duplication cyst, diagnosed in the neonatal period which 'vanished'. What was later confirmed to be a small bowel duplication cyst was not seen on follow-up ultrasounds and thus the patient was managed expectantly until presentation as an emergency. Our case highlights the challenges faced in managing cystic abdominal structures in infancy and the potential consequences of expectant management. We discuss whether cross-sectional imaging or diagnostic laparoscopy should be advocated when duplications cysts are considered amongst the differentials of a lesion on ultrasound.