Arteriolosclerosis (Hyperplastic Type)

Arteriolosclerosis (Hyperplastic Type) is a condition that affects the small arteries and arterioles, which are tiny blood vessels responsible for delivering blood to various organs. This disease mainly involves the thickening of the vessel walls due to the proliferation of smooth muscle cells, leading to a characteristic onion-skin appearance. It primarily occurs in response to severe or malignant hypertension, causing the vessels to narrow and restrict blood flow. The reduced blood supply can damage vital organs such as the kidneys, heart, and brain, potentially leading to serious complications like kidney failure or stroke. This condition is a form of vascular disease that impairs the body's ability to maintain normal blood pressure and organ function.

Arteriolosclerosis (Hyperplastic Type) is characterized by concentric, laminated thickening of the walls of small arteries and arterioles due to hyperplasia of smooth muscle cells and reduplication of basement membranes. It is most commonly caused by malignant hypertension, which induces endothelial injury and stimulates smooth muscle proliferation. This leads to a marked narrowing of the vessel lumen, resulting in ischemia of downstream tissues. Histologically, the hallmark is the onion-skinning pattern of vessel wall thickening. Clinically, this type of arteriolosclerosis is significant because it contributes to acute target organ damage, especially in the kidneys, causing fibrinoid necrosis and rapidly progressive renal failure. It differs from hyaline arteriolosclerosis, which is more typical of chronic hypertension and diabetes mellitus.