Recent posterior fossa tumor resection. There are postsurgical changes of a left retrosigmoid suboccipital craniectomy for posterior fossa tumor resection, with a small amount of extra-axial fluid deep tot he craniotomy flap. There is an enhancing nodular lesion with measuring approximately 15 mm in diameter in the posterior left cerebellomedullary angle cistern region, along the lateral aspect of the fourth ventricle. There is also a 12 mm diameter nodular enhancing lesion more anteriorly in the left cerebellomedullary angle cistern region. There is extensive encephalomalacia in the left cerebellar hemisphere and middle cerebellar peduncle and what may represent a small amount of acute ischemia in the left cerebellar hemisphere. There is no midline shift or herniation. The third and lateral ventricles are not enlarged. The major cerebral flow voids are intact. The orbits are grossly unremarkable. There are skin fiducial markers.
Recent postoperative findings with evidence of residual tumor in the left cerebellomedullary angle cistern region.