Leptomeningeal carcinomatosis (LC) is a rare and devastating metastatic manifestation of both liquid and solid tumors consisting of dissemination of malignant cells with invasion into the meninges. Few options exist in most clinical situations, especially when LC is the presenting sign of occult malignancy. The prognosis is often poor with limited survival. Aims of palliation must be considered the primary goal for most patients. We report a case in which occult metastatic breast cancer presented with neurological symptoms from LC. We discuss diagnosing the primary malignancy when LC is the presenting manifestation as well as treatment, both palliative and cytoreductive. We also focus on those patients with breast cancer that are at highest risk of developing LC.