6-year-old with history of astrocytoma status post craniotomy and chemotherapy. Interval follow-up exam. Postsurgical changes involving the right posterior fossa. Redemonstration of a predominantly extra-axial soft tissue mass at the right cerebellar pontine angle without significant enhancement. Accounting for differences in slice selection through the mass, this is not significantly changed measuring 3.4 x 1.7 cm (series 801 image 19), previously 3.2 x 2.2 cm. The mass crosses midline and encases the vertebral artery. Inferiorly it tracks along the posterolateral aspect of the spinal cord and beyond the field-of-view of this exam. These more inferior components are partially cystic. Anterosuperiorly there is stable extension into the right Meckel's cave and right internal auditory canal.Unchanged right parietal ventriculostomy catheter which approaches midline. The ventricles and sulci are stable and not enlarged. The cisterns remain patent. Normal intravascular flow voids are preserved. New severe opacification of the maxillary and sphenoid sinuses as well as new partial opacification of the right mastoid air cells.
1. Stable appearance of predominantly extra-axial right posterior fossa juvenile pilocytic astrocytoma with extension inferiorly through the foramen magnum and anterolaterally through the skull base foramina.2. Stable appearance of the supratentorial brain without additional suspicious lesion.3. New marked opacification of the paranasal sinuses and right mastoid air cells; correlate for symptoms of sinusitis.