Cobblestone lissencephaly in the setting of congenital cytomegalovirus infection: A case report and review of the literature.

Lissencephaly is a migrational disorder that results in abnormal gyration and cortical lamination. Type 1 lissencephaly is characterized by absent or reduced number of gyri giving the brain a smooth appearance, while type 2 lissencephaly (cobblestone lissencephaly) is described as over-migration of neurons or neuronal precursors beyond the glia-pial limitans giving rise to a cobblestone appearance of the cerebral hemispheres. Both types of lissencephaly are typically thought of as congenital anomalies secondary to genetic defects while cases of lissencephaly due to acquired injury is rare. The few examples that do exist in the literature mainly describe changes in keeping with type 1 lissencephaly. We present here an unusual case of a fetus with brain structural changes consistent with cobblestone lissencephaly with concurrent CMV (cytomegalovirus) meningoencephalitis. Our patient is a 23-week-old stillborn fetus of a 28-year-old G1P0 mother who underwent elective termination of this pregnancy after ultrasound and fetal MRI revealed multiple brain anomalies. Post-mortem examination of the fetus revealed evidence of CMV infection involving multiple systemic organs and the brain. Evidence of malformative lesions included cobblestone appearance of the cerebral hemispheres, enlarged lateral ventricles, and focal polymicrogyria. Normal diploid complement for chromosomes 13, 18, and 21 was revealed by rapid aneuploidy testing. While single case reports of CMV with features in keeping with type 1 lissencephaly have been described in the literature, to the authors' knowledge this is the first example of cobblestone lissencephaly observed in the context of congenital CMV infection.