Which condition is defined as a skin-covered protruding sac containing meninges and CSF?

• A. Meningocele
• B. Myelomeningocele
• C. Myeloschisis
• D. Occulta

Answer: (A)

The key idea is differentiating neural tube defects by what herniates in the sac. When a sac protrudes and is skin-covered, but the sac contains only the meninges and cerebrospinal fluid (CSF) without neural tissue, that is a meningocele. The spinal cord and nerve roots remain in place, inside the spinal canal, while the meninges and CSF herniate into the sac.

In contrast, if the sac contains not only meninges and CSF but also neural tissue such as the spinal cord or nerve roots, the defect is a myelomeningocele, which tends to have more neurologic impairment. If the neural tissue is exposed on the surface without any skin covering, that describes myeloschisis, a more severe open defect. Occulta is a hidden defect with no protruding sac, often with no outward herniation.

So the description of a skin-covered sac that contains meninges and CSF fits meningocele.