Tumor-to-Lesion Metastasis: Case Report of Carcinoma Metastasis to Multiple Sclerosis Lesion

BACKGROUND: The term "tumor-to-lesion metastasis" is an extension of "tumor-to-tumor metastasis," which is a rare but well-documented phenomenon. Tumor metastasis to the meninges and/or central nervous system (CNS) is rare in patents with multiple sclerosis (MS), although MS lesions bear many similarities to the primary tumor microenvironment and metastatic niche. We present the first case of malignant tumor metastasis to MS lesions with …