Neoplasms: Classification, ICP and Characteristics Flashcards
What are primary tumors
Originates in the brain itself, SC or supporting tissues
CNS neoplasms in children are largely 1° in nature
Do not typically metastasize due to the lack of a lymphatic system in the brain
Why does a primary tumor not metastasize very well?
Because the brain is a closed system and the lymphatic system does not transport in to the CNS that is why these tumors do not usually metastasize outside the CNS. This does not mean that they cannot just that they usually do not
What is the difference between the deficits of a brain tumor and other brain pathologies?
You will see progressive focal deficits depending on where in the brain the tumor is located the only difference that we see is that those symptoms become progressive - same symptoms increase is severity
2° Metastatic Brain Tumor: origin and prognosis
Origin: outside the brain
Prognosis: Variable
Do you see focal deficits with secondary brain tumors?
You do not see focal deficits to the same degree that you see with primary. Secondary has already metastasized that means tumor can spread throughout parts of the brain. So you do not see the focal deficits that you would typically see with primary. You will see deficits depending on what part of the brain is affected
What is the difference between predominant location of brain tumors in adults and children
60% of CNS tumors in adults are supratentorial
Brain tumors in children are infratentorial in location
Why is treatment of brain tumors complicated
There are many different types (120)
How is the prognosis of a brain tumor and age different from a concussion?
The younger a person is the more likely they are to recover because the brain continues to develop and can develop around the injury with a concussion, the brain is damage
Tumor Nomenclature: Adenoma
Benign tumor arising from a gland (pituitary adenoma)
Tumor Nomenclature: Blastoma
Malignant tumor with undeveloped (embryonic) cellular characteristics (ie. medulloblastoma or glioblastoma multiforme)
Blastoma can spread
Tumor Nomenclature: Glioma
A benign or malignant tumor that arises from supportive tissue of brain (ie. astrocytoma or oligodendroglioma)
Gliomas can be benign or malignant - come from glia cells
Tumor Nomenclature: Carcinoma
Malignant tumor arising from skin or lining of the GI/GU/Resp systems; ie. lung cancer (small cell carcinoma) or colon cancer (adenocarcinoma)
Tumor Nomenclature: Sarcoma
Malignant tumor arising from connective tissue, blood vessels, or the lymph system; ie. osteosarcoma.
Effects of CNS Tumors
Mechanical displacement of brain and SC
Blockage of CSF circulation
Causes neurologic effects by
Compression of cerebral tissue including cranial nerves
Invasion or infiltration of cerebral tissue
Erosion of bone
Also lead to 2° changes such as cerebral edema and elevated ICP
Why would mechanical displacement of brain and SC with a tumor
As the mass grows you have potential mechanical displacement of the brain and spinal cord depending on where it is located. Basically you have a mass and the larger it grows, it pushes areas of the brain out of the way. Can cause disruption of electrical conductivity
What is Vasogenic Cerebral Edema and what can it cause
Vasogenic means the ability to absorb and release fluid
Leads to seepage of plasma into the extracellular space between the layers of the myelin sheath and axon - if there is extra fluid in there the NTs need to cover a greater surface area to promote electrical mobility —> conduction is impaired
Impairs cellular activity and causes electrochemical instability
Vasogenic cerebral edema may also develop from alterations in the BBB, as in the tumor-facilitated release of vasoactive & endothelial destructive compounds
Cerebral edema causes
inflammation and brain compression
Overtime the brain adapts and the brain tissue actually gets smaller to compensate. Also the CSF decreases and blood flow decreases to the brain.
↓ in the amount of brain tissue (slowly over time in the presence of elevated ICP)
↓ CSF volume
↓ cerebral blood flow volume
Which type of tumor allows brain to adapt to cerebral edema?
This usually happens with slow moving tumors because brain has the time to adapt around it
When will you start to see symptoms of Cerebral Edema?
Few signs and symptoms may be noted initially, but when the brain can no longer compensate, the ↑ ICP leads to more evident symptoms
(Once the brain reaches its ability to adapt then you will really start to see symptoms develop.)
*What are Signs of Elevated ICP
1) Headache
2) Seizures
3) Other signs include vomiting, mental clouding, lethargy & alteration of consciousness
Headache from elevated ICP location and symptoms
Retro-orbital or generalized:
Intensified by activities that raise ICP: Straining, stooping, exercising
May improve during the day
Caused by irritation, traction or compression of pain sensitive structures including blood vessels, venous sinuses, cranial nerves & the dura mater
Often accompanied by nausea, vomiting and papilledema
Seizures and elevated ICP:
Is it common?
Why would it happen
Which type of tumor is it? associated with?
A common initial sign
Produced by discharges from hyperactive cells because you are interrupting the electoral conductivity within the brain
More likely to accompany slow growing tumors
Why are seizures more common with slow growing tumors?
This usually happens with slow moving tumors because brain has the time to adapt around it and you do not develop those immediate symptoms that fast growing tumors show right away
Progression of Signs and Symptoms of CNS neoplasms
Focal deficits may start to appear over time
Will reflect encroachment on the anatomic region
It is the progressive nature of neurologic sx that are the hallmark of CNS neoplasms
a progressive, usually non-variable, character
What are the hallmarks of CNS neoplasms
a PROGRESSIVE, usually NON-VARIABLE, character
Tumor Characteristic: Differentiation
Histologic grade of a tumor
Tumors tend to mimic normal tissue and cellular architecture
Refers to how much the tumor resembles normal cells of the same tissue type
How is differentiation described and which one has a better prognosis
Well-differentiated:
Structure is nearly normal and likely to be benign in nature - looks normal (good sign)
Poorly or un-differentiated:
Structure is abnormal and likely to be malignant - (bad sign)
Benign Tumors are:
Slow growth rate
Non-invasive
Well-differentiated
Low risk recurrence
Malignant Tumors are:
Fast growth rate
Invasive - different parts of brain
Poorly differentiated
High risk recurrence
How are tumors graded
Once a type of cancer is dx, it is graded as to its aggressiveness
Level of differentiation is obtained by biopsy to compare the resemblance to normal cells
What are the 3 Types of grading systems
I-IV grading system
Gleason system
TNM System
