Metastatic spread of systemic neoplasms to central nervous system tumors: Review of the literature and case presentation of esophageal carcinoma metastatic to meningioma

Metastatic spread of a systemic neoplasm to a central nervous system malignancy is a rare but well-documented phenomenon. Over 100 case reports of tumor-to-tumor spread involving the central nervous system have been described since the first report in 1930. Overwhelmingly, intracranial meningioma represents the most common recipient tumor, while breast and lung are the first and second most common donor malignancies, respectively. The propensity for meningiomas to harbor metastatic lesions has been attributed to cell-to-cell adhesion molecules, favorable metabolic environment as well as hormonal and mechanical factors. We distinguish the concepts of true "tumor-to-tumor metastasis" and "tumor collision" and discuss potential non-invasive diagnostic modalities that may aid in preoperatively identifying intracranial lesions harboring distal metastasis. We present the first incidence, to our knowledge, of metastatic esophageal carcinoma spread to intracranial meningioma.