Skull Base Metastasis of Breast Cancer With Oculomotor and Trochlear Nerve Palsy.

Skull base metastatic tumors are rare. Breast cancer in particular can cause bone metastases after a long period of time. A 70-year-old woman presented with multiple cranial nerve palsy. Magnetic resonance imaging revealed a lesion that extended from the orbit to the base of the skull, and the patient was referred to our department. Ophthalmological evaluation showed left visual acuity impairment, left oculomotor nerve palsy, and left trochlear nerve palsy. Endoscopic biopsy performed 5 years after the completion of breast cancer treatment revealed skull base metastases. In unilateral multiple cranial nerve palsy, the possibility of skull base metastases should be considered.