11 month old female with a cerebellar vermis lesion. Expected postoperative changes are again seen from the previous vermian mass biopsy through a small right paramedian occipital burr hole with resolution of the previous pneumocephalus and trace subdural blood products. Redemonstrated is a polypoid non-enhancing right cerebellar vermian lesion with normal T2/Flair signal intensity, which extends into the fourth ventricle and which is not significantly changed. The small hypothalamic lesion and subtle thickening of the tectal plate which narrows the cerebral aqueduct are also not significantly changed.Unchanged small focus of enhancement just above the tectal plate which is suspected to represent normal enhancing pineal tissue.There is a stable right frontal approach ventriculostomy catheter with tip in the midline on the anterior aspect of the septum pellucidum. The ventricles and sulci are within normal limits and there is no midline shift or mass effect. The major cerebral flow voids are intact. There is a fluid in the right greater than left mastoid air cells. There is patchy opacification of the ethmoid air cells bilaterally. The orbits, skull, and scalp soft tissues are grossly unremarkable.
No significant change in the hypothalamic lesion, polypoid cerebellar vermis lesion extending into the fourth ventricle, or the thickening of the tectal plate which narrows the cerebral aqueduct. These lesions may be hamartomatous/developmental especially given their absence of associated signal abnormality or enhancement but recommended continued follow-up.