Which of the following is NOT considered a postganglionic Horner's lesion?

A Pancoast tumor is typically not classified as a postganglionic Horner's syndrome lesion. Horner's syndrome occurs due to disruption of the sympathetic innervation to the eye and surrounding structures, and it can result from lesions at various points along the sympathetic pathway.

In the case of Pancoast tumor, which is a type of lung cancer located at the apex of the lung, it primarily involves the preganglionic sympathetic fibers. It can indeed lead to Horner's syndrome, but only by compressing the sympathetic chain before the synapses have occurred at the sympathetic ganglia. This is characteristic of a preganglionic involvement.

In contrast, postganglionic Horner's lesions occur after the sympathetic pathways have already synapsed at the superior cervical ganglion. Conditions such as carotid artery dissection, internal carotid artery (ICA) aneurysm, and cavernous sinus fistula directly damage or compromise the postganglionic fibers that innervate the eye and face. These conditions typically present with the classic symptoms of Horner's syndrome, such as ptosis, miosis, and anhidrosis when the nerve fibers that have already exited the ganglion are affected.

Therefore, while all choices relate