We have an interesting case of a 30 year old female who had an MRI study for right sensory neural hearing loss. Incidentally found on her scan was a 1.2 cm lesion in the region of the left subthalamic nucleus extending to the cerebral peduncle with mild expansion which appears isointense to gray matter on all sequences with no evidence of enhancement. Single voxel spectroscopy showed elevation of myoinositol. No decreased NAA and no increased choline. A one year follow up MRI showed no changes in size of the lesion. This lesion is felt to represent a hamartoma; however, most hamartomas described in the literature are in the hypothalamus. Has anyone seen a hamartoma or gray matter heterotopia in this location? We will appreciate your input.
Midbrain Hamartoma
