A 54-year-old woman consulted because of left-sided weakness of two months’ duration. She had a past history of breast cancer that was treated 2 years ago, but currently has no signs of cancer elsewhere in her body. Brain MRI showed a large tumor in the right parietal area. 

The patient underwent surgery to remove the tumor. It was not difficult for the surgeon to distinguish between brain and tumor, because the tumor was most likely a brain metastasis, meaning it came from somewhere else in the body and did not originate from the brain. This is why the appearance of the tumor looked different from the brain. 

The patient’s weakness improved after the surgery, and improved even more after physical therapy. The biopsy result was metastatic adenocarcinoma, which was most likely a tumor that spread to her brain from the breast cancer. She underwent radiation therapy as additional treatment for the tumor.