Abstract
Two patients presented with metastatic pineal tumors. A 69-year-old man had gait disturbance, dementia, and urinary incontinence but no history of previous malignancy. Magnetic resonance imaging of the brain revealed a 23-mm tumor in the pineal region and obstructive hydrocephalus. A 37-year-old man had been treated for thyroid cancer. He presented with vomiting and consciousness disturbance. Brain magnetic resonance imaging revealed a 28-mm pineal tumor associated with intratumoral hemorrhage and accompanying obstructive hydrocephalus. Both patients underwent neuroendoscopic biopsy and third ventriculostomy through the foramen of Monro, resulting in reliable histological diagnoses and subsidence of hydrocephalus.