Many progressive neurologic diseases may be associated with cystic degeneration of the putamen, but Wilson's disease is the most likely of these to be emphasized on the USMLE.

The putamen (Choice B) can be identified on coronal sections (either in gross specimens as above or on imaging studies) in a location immediately deep (medial) to the insula and lateral to the globus pallidus and internal capsule.

Show Explanatory Sources

(Choice A)  The globus pallidus is the orange-colored structure on the above image immediately medial to the degenerated putamen.  It is considered part of the basal ganglia along with the caudate and putamen.

(Choice C)  The internal capsule is the white matter structure that separates the globus pallidus and putamen from the caudate nucleus anteriorly and from the thalamus posteriorly on coronal sections.

(Choice D)  In its full three dimensional structure, the caudate nucleus is a curved or "C-shaped" structure that can be identified in the inferolateral walls of the anterior horns of the lateral ventricles.  However, only a small cross-section is visible in the image above next to the lateral ventricles.  This structure is affected in Huntington's disease.

(Choice E)  The amygdala is a group of neurons in the medial temporal lobe located adjacent to the hippocampus that plays a role in the limbic system.  The amygdala can be identified on the image above as the circular grey matter structures in the medial temporal lobe immediately inferior to the globus pallidus and putamen.  The amygdala mediates fear and some sympathetic stimulation in humans.

Educational Objective:
Wilson's disease can cause cystic degeneration of the putamen as well as damage to other basal ganglia structures.  The putamen is located medial to the insula and lateral to the globus pallidus on coronal sections.