<prompt> Most common cause of leptomeningeal spread is from which of the followingBreastThyroidBoneLiver  <response>: Leptomeningeal metastases, also know as carcinomatous meningitis, refers to the spread of malignant cells through the CSF space. These cells can originate from primary CNS tumors e.g. This aicle has a focus on subarachnoid space involvement. Refer to 