Antenatally diagnosed duplication cyst of the tongue: modern imaging modalities assist perinatal management

When a foetal abnormality is detected during routine antenatal screening, further information is required in order to plan the remainder of the pregnancy and perinatal management. If a lesion is detected in the foetal mouth or neck, there may be compromise of the foetal airway. The ex-utero intrapartum (EXIT) procedure has recently been developed to allow lifesaving foetal surgery to be performed during delivery of such cases whilst relying on placental support. Detailed antenatal assessment is essential when planning the EXIT procedure, and modern imaging modalities may be implemented. We illustrate this by reporting a rare case of enteric duplication cyst arising from the base of the tongue, which was detected on routine antenatal ultrasound scan. Subsequent imaging using foetal MRI and colour Doppler ultrasound reassured us that the foetal airway was patent, and an EXIT procedure was avoided.