Which condition describes a sac containing spinal cord and meninges protruding through a vertebral defect?

• A. Myelomeningocele
• B. Micromelia
• C. Proboscis
• D. Lemon sign

Answer: (A)

This describes an open neural tube defect where the spinal cord and meninges protrude through a vertebral defect, forming a sac. That specific condition is myelomeningocele, the more severe form of spina bifida in which neural tissue lies in the sac. It stems from failure of the neural tube to close early in development, allowing the spinal contents to herniate. In prenatal imaging you’d see a sac over the spine containing neural tissue, often at the lumbar or lumbosacral level, and it’s commonly linked with other issues like Arnold-Chiari II malformation and hydrocephalus. Other terms refer to different problems: micromelia means unusually short limbs; proboscis is a severe facial anomaly; lemon sign describes a skull contour seen on ultrasound with some open neural tube defects, but it’s not the description of a spinal sac itself.