Two cases of intraoperative cerebral hemorrhage caused by undiagnosed metastatic brain tumors

: The authors report two cases of intraoperative cerebral hemorrhage caused by metastatic brain tumors. Delayed recovery from general anesthesia and neurological deficit were found in these patients. Brain CT in case 1 showed bilateral subdural hemorrhage and parenchymal massive hemorrhage in case 2. It is thought that the causes of hemorrhage are due to the changes in morphology of vessels, deterioration in cerebral circulatory regulated system, and increased intracranial pressure caused by tumors. Since the incidence of metastatic brain tumor has increased with prolonged survival time induced by progress in cancer therapy, preoperative brain examination and careful attention to vital signs during anesthesia are needed.