You may hear several similar-sounding words — meningocele, encephalocele, meningoencephalocele. They describe the same general problem but differ by one crucial detail: what is inside the sac. This single detail is one of the most important factors in your child's outlook.
The words, decoded
- Meningocele (cranial meningocele): The sac contains only the meninges (the membranes covering the brain) and cerebrospinal fluid (CSF) — no brain tissue.
- Encephalocele: A broad term for the protrusion; in everyday use it often implies that brain tissue is involved.
- Meningoencephalocele: The sac contains meninges, CSF, and brain tissue.
You may also see "cephalocele" used as an umbrella term for all of these.
Why "what's inside" matters so much
The single biggest reason this distinction matters: defects that contain only membranes and fluid (meningocele) generally have a much better outlook than those that also contain brain tissue. When functioning brain tissue is herniated into the sac, there is more potential for neurological effects, and decisions about surgery become more delicate.
This is also why the size of the sac can be misleading. A large sac might contain mostly fluid (better outlook), while a smaller sac might contain a meaningful amount of brain tissue. The sac's size does not reliably tell you its contents — only imaging does.
How doctors find out what's inside
Detailed imaging, especially MRI, shows whether the sac contains only fluid and membranes or also brain tissue, and how that tissue connects to the rest of the brain. This is a central reason your team will want high-quality scans before counseling you on outlook or surgery.
What this means for parents
If your team uses the word meningocele, it generally signals a more favorable situation than meningoencephalocele. But "favorable" still means individualized care, imaging, and follow-up. Ask your team directly: "Is there brain tissue in the sac, and if so, how much and is it functional?"
Sources
- StatPearls (NCBI Bookshelf) — Encephalocele
- Children's Wisconsin (Fetal Concerns Center) — Encephalocele
- CHOP — Encephalocele
- ScienceDirect (Topics) — Encephalocele overview