Fetal scalp cyst or small meningocele: differential diagnosis with three-dimensional ultrasound.

BACKGROUND

Prenatal differential diagnosis of fetal scalp cystic masses is challenging and mainly includes small meningoceles and epidermal cysts.

CASE: A second-trimester anatomy scan revealed an extracranial cystic mass measuring 17 × 12 × 10 mm in the fetal occipital region. Three-dimensional datasets were obtained transabdominally and off-line analysis revealed a connection between the cyst and the subarachnoid space through a 5-mm skull defect. The diagnosis of a small meningocele was further confirmed by magnetic resonance imaging in the infant.

CONCLUSION

Prenatal three-dimensional ultrasound can be a useful adjunct in the prenatal differentiation between small meningoceles and epidermal cysts.