American Board of Pathology (ABPath) 2025 – 400 Free Practice Questions to Pass the Exam

A true aneurysm involves all three layers of the arterial wall: the intima, media, and adventitia. This type of aneurysm occurs when there is a weakening of the artery wall, leading to a dilation that encompasses the full thickness of the vessel.

In the case of a true aneurysm, the pathophysiology is often associated with factors such as hypertension, atherosclerosis, or genetic abnormalities that weaken the structural integrity of the vessel wall. As the aneurysm expands, it carries all three layers outward, which is critical for understanding the potential complications and risks associated with the aneurysm, including rupture or dissection.

The involvement of all three layers is significant because it reflects the nature of the artery's structural disease. If only one or two layers were involved (as suggested by some of the other choices), it would indicate a different type of vascular abnormality, such as a pseudoaneurysm, where a breach in the vessel wall allows blood to leak out but not through all the layers. This distinction is crucial for diagnosis and treatment strategies in vascular pathology.