A small MRI clue may help tell brain tumors apart
Original title: The "Pearl Sign": A conventional MRI feature for distinguishing brain metastasis from glioblastoma and primary CNS lymphoma.
How far along is this research?
- Lab cells
- Animals
- Review
- Tested in people
This was tested in people. That is the most reliable kind of research we share.
Doctors only looked back at scans people already had, so this clue is not proven yet.
The short version
A pattern on MRI scans may help doctors tell cancer that spread to the brain from other brain tumors.
What was studied. Doctors looked back at MRI scans from 281 adults whose brain tumor type was confirmed by lab tests. The group had 88 people with cancer that spread to the brain, 126 with glioblastoma: A glioma that is given grade 4. Grade 4 is the highest grade there is. The tumor grows fast. Treatment usually starts soon after it is found. It often means surgery, and then radiation and chemotherapy. See the glossary, and 67 with CNS lymphoma. Two radiologists checked each scan for the Pearl Sign, a ring of small fluid pockets near the tumor's edge.
What they found. The Pearl Sign showed up in 60.2% of tumors that had spread from cancer elsewhere. It showed up in only 6.3% of glioblastomas and 1.5% of lymphomas. When doctors added this sign to their usual scan clues, they picked the right tumor type 84.7% of the time, up from 71.3%.
What this means, and what it doesn't
What it could mean: If your MRI shows this pattern, it may point toward cancer that spread to the brain. That could help your care team choose the right next step sooner. The sign is easy to spot on a normal MRI, so no special scan is needed.
What it doesn't mean: This is not a treatment, and it is not a cure. It is a reading clue for doctors, not a test you can ask for. The team only reviewed old scans at one hospital, so the sign still needs testing elsewhere. Many tumors that had spread did not show the sign at all. A tissue sample is still how doctors confirm what a brain tumor is.
Source: PubMed, November 3, 2026 · Read the original
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