Bronchopulmonary sequestration in a monochorionic diamniotic preterm twin.

This is a unique case with an initial suspicion of twin-to-twin transfusion syndrome in monochorionic twins, leading to hydrops fetalis. The recurrence of left pleural effusion complicated the initial diagnosis. An incidental finding of a lung lesion revealed bronchopulmonary sequestration on further investigation. A customised dexamethasone regimen successfully managed the recurrent pleural effusion, avoiding the need for early thoracic surgery.