Which term describes a tear in the intimal lining with a false lumen?

• A. Embolism
• B. Aneurysm
• C. Stenosis
• D. Dissection

Answer: (D)

Dissection is a tear in the intimal lining of a vessel that lets blood enter the wall and split its layers, creating a true lumen and a separate false lumen. The intimal tear allows propagation of the dissection along the vessel, which can compromise branches and lead to ischemia or rupture. This is different from an embolism, where material travels to occlude downstream vessels without forming a new lumen; from an aneurysm, which is a dilatation of the vessel wall; and from stenosis, which is narrowing of the lumen without a separated wall. Clinically, dissection may present with sudden severe pain and signs of ischemia, and imaging often reveals an intimal flap separating two luminal channels.