Systemic Tumour Metastasis to Cerebral Meningioma: Literature Review with a Case Report

"Tumour-to-tumour metastasis" (TTM) refers to the metastatic deposition from a primary neoplasm to another type of neoplasm within the same patient. While meningiomas have been reported to be the most common intracranial host of malignant metastases, breast and lung carcinomas have been the most frequently reported systemic donor tumours. In the relevant literature, some of the characteristics of meningiomas have been suggested to provide a favourable environment for the metastasis. Furthermore, some factors, such as immunological and hormonal factors, that are thought to make significant contribution to this event prompt research interest. Physiology-based neuroimaging methods, such as perfusion MRI (p-MRI) and proton spectroscopic MRI (proton s-MRI) could be efficient in differentiating TTM characterisation. The current case of this study, a primary breast carcinoma metastasising into two intracranial meningiomas, is presented with a list of pertinent cases reported to date, and literature is reviewed.