Last Updated: 03/28/17
- Tumor Development
- NF2 Tumor Types by Location
- Bilateral Vestibular Schwannoma
- Additional Brain Tumors
- Spine Cord Tumors
- Peripheral Nerve Schwannoma
- Skin Surface
- MRI's of NF2 Tumors
- Tumor Descriptions
- NF2 Tumor Growth
1. Tumor Development
Neurofibromatosis Type 2 (NF2) results in the growth of different tumor types that grow as Benign (Noncancerous),
but there is a chance they can become Malignant (Cancerous) as they grow larger.
Based on an individual's exact NF2 mutation (variation), tumor development follows a typical pattern, even if tumor growth rate and
development can increase or decrease at some rate due to life choices. The mutation however is the biggest part of the tumor growth pattern.
Tumors that grow along the PNS (Peripheral Nervous System) and along the spinal cord [Plotkin, 2012] have a slower rate of
growth than brain tumors.
2. NF2 Tumor Types by Location
Tumors might be; Schwannoma, Meningioma, or Glioma. Tumor formation types can develop, including some combination of the following 5 categories of tumor growth:
- Bilateral Vestibular Schwannoma (VS), sometimes referred to as Acoustic Neuroma (AN):
Schwannoma growth on both, the left and right, Vestibular Nerve
- Additional Brain Tumors: Schwannoma, Meningioma and Glioma (Astrocytoma or Ependymoma)
Spinal Cord Tumors: Schwannoma, Meningioma and Glioma (Astrocytoma or Ependymoma)
Peripheral Nerve Schwannoma:
- Schwannoma on Cranial Nerves:
Schwannoma growth in the brain is rarely limited to just the Vestibular Nerves
- Intracranial Meningioma:
Meningioma can easily develop throughout the brain.
- Cerebellum (lower brain):
Glioma (Astrocytoma or Ependymoma)
Schwannoma on nerves outside of the brain and spine which can only be seen with MRI.
Skin Surface: Cutaneous Schwannoma (also called Dermal Schwannoma) and Subcutaneous Schwannoma
Note: It is not possible to tell the difference between Schwannoma, Meningioma or Neurofibroma in a MRI.
Schwannoma and Meningioma are easily identifiable in surgery. While Schwannoma and Neurofibroma are different, sometimes the difference
is not seen until cell biopsy is done after surgery. All of these things result in inaccurate diagnosis of the type of NF2 a person has.
Some research papers imply a person with NF2 can develop Neurofibroma skin tumors.
3. MRI's of NF2 Tumors
|Bilateral Vestibular Schwannoma (VS)
||VS - Typical or Multi-lobulated
||Upper Cranial Meningiom
|Meningioma or Schwannoma?
4. Tumor Descriptions
- Schwannoma: These are typically Benign (non-Cancerous) tumors that are the result of an abnormal overgrowth of a Schwann Cell in a nerve cells Myelin Sheath.
Meningioma: These develop as Encapsulated and Benign Tumors, as these tumors reach different sizes as a result of simple growth or treatment(s)
of Radiation. Either way, Meningioma can have dangerous or even fatal consequences. Safety typically depends on the classification from WHO
the World Trade Organization. As a tumor grows larger the classification of the tumor reaches the next grade level and increased
speed of growth.[Tew, 2013]
- Vestibular Schwannoma (VS), also known as Acoustic Neuroma (AN): The Vestibular Nerve attaches the Vestibule to the brainstem,
between these two points the nerve passes between a bone structure, and because of this results in typically a pear-shaped
Schwannoma tumors alone the Vestibular nerve are not always the result of the condition NF2, for individuals who develop Schwannoma
from NF2 the tumors might be either 1) Typical, which is overgrowth of one Schwann cell, or 2) Multi-lobed masses which are combined
Schwann cells of possibly different parts of the Vestibular Nerve, but can be more complex.
When individuals have VS, but do not have NF2, the tumors are always Typical Schwannoma.
- Learn more about VS
- Learn more about Nerves
- Central Nerve System Tumors: These are tumors that grow on Cranial Nerves (CN) (nerves within
the Brain) and along the Spinal Cord; these are most frequent occurring Schwannoma tumors for NF2.
- Spinal Cord Tumors: Tumors that grow along the Spinal Cord [Plotkin, 2012]
have a slower rate of growth than brain tumors.
- Peripheral Nervous System Tumors: Tumors that grow along the PNS (Peripheral Nervous System)
[Plotkin, 2012] have a slower rate of growth than brain tumors. These
are tumors that grow on nerves outside of the Brain and Spinal Cord and along the rest of the body, there are two
forms of these:
- Cutaneous Schwannoma: These are tumors that grow over the skin and but generally are not painful.
- Subcutaneous Schwannoma: These are tumors that grow anywhere under the skin and generally are painful.
- WHO Grade 1: When these tumors start to grow they are slow growing, Benign.
- WHO Grade 2: These are Atypical tumors have a higher rate of regrowth if surgically removed.
- WHO Grade 3: These tumors are Malignant / Anaplastic.
- Astrocytoma: A type of glial cells that can start to grow in the Cerebrum,
but do grow further than the Spinal Cord
Tumor growth rates can vary dramatically. Different growth rates are the results of:
- Genetics: Mutation and Natural Life Factors
- Environmental and Lifestyle
While genetics play a big role in tumor growth rate, other things can make additional variations on expected
growth. Surgery stress and radiation are now accepted reasons for tumor growth, other issues including hormones
are also believed to be a factor responsible in increased tumor growth.
As we grow, we create new cells, each with a copy of our original set of DNA. Sometimes this copying process is
imperfect, leading to a gene mutation that causes the gene to code for a slightly different protein. Some
mutations are harmless, some can be helpful, and others give rise to disabilities or conditions. [NIH. Brain Basics]
ii. Environmental and Lifestyle
Genes are not the only determinants of how our bodies function. Throughout our lives, our genes can be affected
by the environment. In medicine, the term environment includes not only our physical surroundings but also
factors that can affect our bodies, such as sleep, diet, or stress. These factors may act alone or together
in complex ways, to change the way a gene is expressed or the way messages are conducted in the body.
- Plotkin, S. R., Bredella, M. A., Cai, W., Kassarjian, A., Harris, G. J., Esparza, S., ... & Mautner, V. F.
(2012). Quantitative assessment of whole-body tumor burden in adult patients with neurofibromatosis. PloS one, 7(4), e35711.
- Evans, D. Gareth R., and Sarah Louise Ingham. "Reduced life expectancy seen in hereditary diseases which predispose to early-onset tumors." The application of clinical genetics
6 (2013): 53. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3735038/
National Institutes of Health (NIH). 'Brain Basics' As of: July 17, 2014
- Tew, John MD. Mayfield Brain & Spine. University of Cincinnati Department of Neurosurgery, Ohio. Meningiomas. (February 2013)