Reason: 6 year old with history of juvenile pilocytic astrocytoma s/p chemotherapy - change in mass? History: JPA. There is redemonstration of postoperative changes within the right posterior fossa. There is redemonstration of a predominantly extra-axial soft tissue mass at the right cerebellopontine angle measuring approximately 3.7 x 2.3 cm in greatest axial dimensions on 701/19, not significantly changed compared to multiple remeasurements dating back to 9/22/2015 as not all prior reference measurements are available. For example, on the 3/23/2016 exam, the mass remeasures 3.9 x 2.2 cm. There is redemonstration of encasement of the vertebro basilar arteries at this level, as well as extension into right Meckel's cave and internal auditory canal. Additional lobule of the tumor extends caudally along the dorsal lateral aspect of the cord, extending out of the axial field-of-view. Cystic components more inferiorly remain unchanged in size. There is no significant corresponding enhancement. There is persistent significant mass effect upon the caudal brainstem and upper cord.There is a right posterior parietal approach ventriculostomy catheter stable position, with the tip of the catheter near the right foramen of Monro. The lateral and third ventricles are stable and decompressed. There is no evidence of acute infarct. There is no midline shift or herniation. The major cerebral flow voids are intact. There is prominent mucosal thickening in the sphenoid sinuses bilaterally. Both palatine tonsils are somewhat prominent, likely within normal limits for a patient this age.
1. Continued stable appearance of predominantly extra-axial right posterior fossa mass, with continued mass effect upon the caudal brainstem and upper cord.2. Interval significant bilateral sphenoid mucosal thickening which is nonspecific. Please correlate clinically.