[Medial cleft lip: one diagnosis masking another].

UNLABELLED: Median cleft lip and palate are one of the facial manifestations of holoprosencephaly, a brain malformation resulting from a defect in the development of the prosencephalon, the embryonic precursor of the forebrain. It can occur in isolation or as part of a broader pattern of malformation in many different syndromes. The diagnosis of holoprosencephaly requires a complete malformative assessment. FIRST CASE: a newborn baby seen at birth for a median cleft lip associated with a complex craniofacial malformation. The search for malformations revealed the absence of the median cerebral structure and trisomy 13. The baby died at 48 h. SECOND CASE: A 28-day-old newborn baby consulting for a median cleft lip and palate. The brain ultrasounds showed no anomalies of the median cerebral structure. The malformative assessment revealed no other malformation. DISCUSSION: Holoprosencephaly is a complex developmental brain malformation. From the advances in neuroimaging and genetics, our understanding of the etiology and pathogenesis of this condition has advanced dramatically. This advance should lead to improved management of common medical complications and more optimal family counseling. Surgical treatment is the preferred therapy for viable malformations.