Breast adenocarcinoma metastatic to epidural cervical spine meningioma: case report and review of the literature.

While several cases of cancer metastatic to cranial meningiomas have been reported, metastasis to spinal meningioma has been reported only once, and a mechanism for such metastases has not been investigated. We report a case of breast carcinoma metastatic to an epidural cervical meningioma, summarize the literature on metastases to central nervous system meningiomas, and suggest a possible mechanism. Our patient, a 55-year-old woman, presented with difficulty walking, back pain, and quadriparesis. Magnetic resonance imaging revealed an enhancing C3-4 epidural lesion and an L4 compression fracture. Because of concern that the fracture and epidural lesion might represent metastases, we performed a metastatic work-up, which revealed a right breast mass. The patient underwent C3-C4 laminectomies and an epidural lesion was encountered. Intraoperative frozen section revealed mixed meningioma and breast adenocarcinoma. A gross total resection was achieved and the patient subsequently received spinal irradiation and hormonal therapy. Whereas a literature review revealed numerous reports of metastases to cranial meningiomas, this represents only the second reported case of such pathology in the spine. Mechanisms of this unusual process likely include meningiomas' vascularity, meningiomas' slow growth providing nutrient availability, and perhaps, as suggested by our analysis, E-cadherin expression by both meningiomas and breast cancer. Metastasis to meningioma must be considered in an epidural spinal lesion in all patients with a known malignancy, with surgical aggressiveness tailored to the intraoperative pathologic diagnosis.