Brain Tumor: Primary vs. Metastases

[mrmandrake]

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Hey guys,

I've read a couple of different sources: FA, RR Path, HY neuro and there doesn't seem to be a consensus on whether metastatic brain tumors are more common than primary brain tumors. FA says 50/50, HY neuro gives the edge to primary tumors at 66%, and RR Path gives the edge to metastatic brain tumors saying they are the "most common brain malignancy", whatever that means.

Does this even matter at all? It just bothers me so I'm wondering what the definitive source is. Thanks guys.

 

[username456789]

Hey guys,

I've read a couple of different sources: FA, RR Path, HY neuro and there doesn't seem to be a consensus on whether metastatic brain tumors are more common than primary brain tumors. FA says 50/50, HY neuro gives the edge to primary tumors at 66%, and RR Path gives the edge to metastatic brain tumors saying they are the "most common brain malignancy", whatever that means.

Does this even matter at all? It just bothers me so I'm wondering what the definitive source is. Thanks guys.

I came across this discrepancy too recently. In addition to all of these, Kaplan Qbank had a question about brain mets, and in the answer description it mentioned that mets are slightly more common than primaries . . . then in the next tab over in the learning objectives or whatever, it said it was 50/50. So even Kaplan can't agree with itself.

I'd say in my uneducated opinion that at the very least it's important to know that mets are probably just about as prevalent as primaries. In addition, any time you have a question about a mass at the junction between gray and white matter in the cerebrum, you should assume mets until proven otherwise.

 

[mrmandrake]

I came across this discrepancy too recently. In addition to all of these, Kaplan Qbank had a question about brain mets, and in the answer description it mentioned that mets are slightly more common than primaries . . . then in the next tab over in the learning objectives or whatever, it said it was 50/50. So even Kaplan can't agree with itself.

I'd say in my uneducated opinion that at the very least it's important to know that mets are probably just about as prevalent as primaries. In addition, any time you have a question about a mass at the junction between gray and white matter in the cerebrum, you should assume mets until proven otherwise.

Awesome. I'll make a note of that last tip. Thanks.

 

[username456789]

No problem. Hopefully the way I worded that wasn't overly strong. Obviously you have to take into account the clinical scenario. But if it's not clear (either they don't give you much more information than that, or they do but you can't seem to make sense of the other given info), a mass at the white/gray junction is usually a big clue that it's metastatic disease.

This is what we were taught in path, and it was the key to identifying the correct answer in the aforementioned QBank question.

 

[vicinihil]

Definitely. If you see lots of stuff between the white and grey matter it's most likely a met.

Remember this mnemonic for Ring Enhancing Lesions in the brain

M(etastasis)
A(bscess)
G(lioma)
I(nfarcct)
C(ontusion)

D(emyelination)
R(esolving hematoma)

The most important is probably the first three.

 

[illixir]

In general metastasis is always the most common cancer of an organ is what I was taught except for a few, I think kidney is one, maybe breast, any others?