A rare case where lung cancer spread into a kidney tumor but not a brain tumor
Original title: Selective Tumor-to-Tumor Metastasis of the LCNEC Component of a Combined Lung Carcinoma to Clear Cell Renal Cell Carcinoma Despite a Concurrent Meningioma.
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.
This is a report about what doctors saw in one patient, not a test of any treatment.
The short version
In one man, lung cancer spread into a tumor in his kidney, but it did not spread into the brain tumor he already had.
What was studied. This is a report about one patient. He was a 65-year-old man with a meningioma, a brain tumor, that had come back. Doctors also found a spot on his right lung and a mass on his left kidney.
What they found. The lung tumor turned out to be a mix of two cancer types. One type is called large cell neuroendocrine carcinoma. When doctors removed part of the kidney, they found a small, separate patch of cancer sitting inside the kidney tumor. Special lab stains pointed to that patch coming from the neuroendocrine part of the lung cancer. The brain tumor did not have this spread in it.
What this means, and what it doesn't
What it could mean: Cancer can sometimes spread into another tumor already growing in the body. It can also pick one tumor and not another. This is why doctors look closely at tissue under a microscope instead of assuming what a new spot is. For a patient, a new finding may not be what it first looks like.
What it doesn't mean: This is not a treatment, and it does not change anyone's care today. It is a single case report about one person. That is one of the earliest and weakest kinds of medical report. It cannot tell you what will happen to you or to anyone else. It is not a cure and it is not a step toward one. The doctors themselves call this pattern extremely rare.
Source: PubMed, July 13, 2026 · Read the original
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