Isolated dural metastasis from colon cancer.

We report a case of isolated dural metastasis from colon cancer. Neuroradiologic and intraoperative findings indicated that the tumor was extra-axial, and histopathologic examination resulted in the correct diagnosis. Notable neuroradiologic findings of the present dural-based tumor were: diploic fat MRI signal disappeared in the tumor associated calvaria where bony change was absent on bone-window CT; abnormal subgaleal and epidural tissues were seen on MRI, both of which contained clusters of adenocarcinoma cells histopathologically. These findings suggest an infiltrative, malignant character, and help to differentiate between benign and malignant dural-based tumors.