During a cholecystectomy, a 74-year-old woman becomes hypotensive. What is the likely morphologic lesion resulting from this incident?

The scenario described involves a hypotensive event during surgery, which can lead to ischemia, particularly in vulnerable areas of the brain. In this context, the most relevant morphologic change associated with such episodes, particularly in older patients, is the presence of lacunar infarcts in the basal ganglia.

Lacunar infarcts are small, deep brain infarcts that result from the occlusion of small penetrating arteries due to chronic hypertension and lipohyalinosis. Hypotension during surgery can compromise blood flow, especially to these deep structures, and lead to small ischemic lesions.

Enlarged neurons in the hippocampus would typically be seen in conditions like status epilepticus or in cases of neurodegeneration, rather than as a direct result of hypotension. Posterior pituitary necrosis could suggest issues like Sheehan syndrome, which arises from severe post-partum hemorrhage, not from surgical hypotension. Rupture of a berry aneurysm would lead to subarachnoid hemorrhage and not directly correlate with transient hypotension during a procedure.

Thus, given the context of surgical hypotension, the associated risk of ischemic changes in the brain primarily points to lacunar infarcts in the basal ganglia as the most likely