RESUMO
Diastematomyelia is a type of closed spinal dysraphism in which there is splitting of the spinal cord. It is a rare entity that accounts for less than 3% of closed spinal dysraphisms and affects females 1.3 to 6 times more frequently than males. Lesions are usually found in the lower thoracic and upper lumbar regions. It is characterised by two hemicords separated by a bony or cartilaginous spur. In most cases, it is an isolated malformation with a favourable prognosis. However, it may be associated with other abnormalities and sonography is the imaging test par excellence for early prenatal diagnosis. We report a case of diastematomyelia diagnosed by prenatal sonography at 24 weeks' gestation. Amniotic fluid alpha-fetoprotein (AF-AFP) was normal, while amniotic fluid acetylcholinesterase (AF-AChE) was positive. After birth, the diagnosis was confirmed with magnetic resonance imaging (MRI). The anomaly was associated with a spinal lipoma, tethered cord and dermal sinus. A review of all the cases described in the literature to date is carried out.