Onion skin lesion in vessels is seen in –
**Core Concept**
Onion skin lesions, also known as laminated or layered lesions, are a characteristic histopathological feature observed in certain vascular conditions. These lesions are composed of concentric layers of fibrinoid material and inflammatory cells that surround a central vessel, resembling the layers of an onion.
**Why the Correct Answer is Right**
The onion skin lesion is typically seen in malignant hypertension, where there is a severe and rapid increase in blood pressure that leads to damage to the blood vessel walls. The resulting lesions are composed of layers of fibrinoid material, which is a type of protein that accumulates in damaged blood vessels. The inflammation and fibrinoid deposition lead to the characteristic onion skin appearance under microscopic examination.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because onion skin lesions are not typically associated with atherosclerosis, which is a condition characterized by the buildup of plaque in the blood vessels. Atherosclerosis may lead to narrowing of the blood vessels, but it does not result in the characteristic onion skin appearance.
**Option B:** This option is incorrect because onion skin lesions are not typically seen in vasculitis, which is a condition characterized by inflammation of the blood vessels. While vasculitis can lead to damage to the blood vessels, it does not typically result in the characteristic onion skin appearance.
**Option C:** This option is incorrect because onion skin lesions are not typically associated with thromboangiitis obliterans, which is a condition characterized by inflammation of the small and medium-sized blood vessels. This condition may lead to damage to the blood vessels, but it does not result in the characteristic onion skin appearance.
**Clinical Pearl / High-Yield Fact**
Onion skin lesions are a hallmark of malignant hypertension, which is a medical emergency that requires immediate attention. The presence of these lesions can help diagnose malignant hypertension and guide treatment.
**Correct Answer: D**