A 21-year-old woman presented with headache, vomiting, dysarthria and mild hemiparesis on the right side. CT scan revealed a round well-circumscribed high density lesion in the ventro-lateral portion of the pons. MRI showed characteristic hemosiderin rim in T2 weighted image. Twelve days after initial bleeding, she developed conscious disturbance, right hemiplegia, MLF syndrome, left abducens and facial palsy. MRI demonstrated the new hematoma extending from the pons to the midbrain. The suboccipital transvermian approach was employed in an attempt to remove the hematoma and the angioma under monitoring of auditory evoked potential. Histological examination revealed abnormal vessels of the cavernous angioma. Surgical indication of the brain stem cavernous angioma is still controversial, especially in a patient with minor neurological deficits. Refinement of neuroradiological procedures and microsurgical technique may bring about favorable results under a more aggressive approach. However, further investigation of the natural history is mandatory in patients with these lesions.
