A female neonate is noted at birth to have a gross deformity of her lower back. Examination of the subcutaneous lesion reveals disorganized neural tissue with entrapment of nerve roots. What is the appropriate diagnosis?

Neural tube defects (dysraphic anomalies) reflect impaired closure of the dorsal aspect of the vertebral column. These abnormalities are classified according the extent of the defect, ranging in severity from spina bifida occulta to meningocele, meningomyelocele, and rachischisis. Spina bifida (choice D) is restricted to the vertebral arches and is usually asymptomatic. Meningocele (choice A) permits protrusion of the meninges as a fluid-filled sac. Meningomyelocele (choice B) exposes the spinal canal and causes the nerve roots to be entrapped. Rachischisis (choice C) is an extreme defect, often without a recognizable spinal cord. Syringomyelia (choice E) is a congenital malformation, in which a tubular cavitation (syrinx) extends for variable distances along the entire length of the spinal cord.Diagnosis: Neural tube defect, meningomyelocele