Normally we would suggest a primary tumor of hypophysis (macroadenoma or craniopharyngioma), but the sudden onset of vision loss and presence of other lesions in the cerebellar region with a history of breast cancer were strongly suggestive of metastases. Breast cancer is known to metastasize into the brain, with intraparenchymal and also dural spread. 

In the next 3 months, the patient underwent chemotherapy and whole brain radiotherapy with almost complete resolution of the lesions.