Presentation
24 weeks pregnancy for routine anomaly scan
Patient Data
Ultrasound findings of fetal head and face include a monoventricular cavity of CSF with absent midline structures i.e, corpus callosum and falx cerebri. Thalami are fused. Some residual peripheral rim of brain tissue is noted. The brainstem and cerebellum are normal. A median cleft lip and hypotelorism can also be appreciated.
Case Discussion
Above mentioned findings are likely in keeping with alobar holoprosencephaly. It is the most severe form of holoprosencephaly with less severe forms being semilobar and lobar types. It results from incomplete cleavage of the prosencephalon.
Facial abnormalities associated with holoprosencephaly include cyclopia, ethmocephaly, cebocephaly, midline cleft lip, lateral cleft lip, and hypotelorism.