<s>[INST] context: Buerger's disease (thromboangiitis obliterans) is characterized by segmental acute and chronic inflammation of intermediate and small aeries. This disorder almost always occurs in cigarette smokers at a young age (usually below 35years) and is often associated with HLA-A9,B5 genotypes. It used to be found exclusively in men, but recently there has been an increase in the number of repoed cases in women. The vessels primarily affected are in the extremities, and this leads to painful ischemia and gangrene of the legs and arms due to thrombosis. Histologic sections reveal an acute inflammatory infiltrate involving the entire wall of the vessel. In contrast to atherosclerosis, small microabscesses may be seen within thrombi. The inflammation leads to intimal proliferation that obliterates the lumen and causes pain. The disease may regress on cessation of smoking. In contrast, granulomatous inflammation with giant cells involving blood vessels can be seen with temporal aeritis orTakayasu's aeritis. Fragmentation of neutrophils surrounding blood vessels is called leukocytoclastic vasculitis, the differential for which includes microscopic polyaeritis nodosa, Henoch-Schonlein purpura, Wegener's granulomatosis, and Churg-Strauss syndrome. [/INST] question: A 30-year-old male smoker presents with gangrene of his extremities. Which one of the following histologic findings from a biopsy of the blood vessels supplying this area would be most suggestive of the diagnosis of Buerger's disease? | options: A: Granulomatous inflammation with giant cells B: Fibrinoid necrosis with overlying thrombosis C: Focal aneurysmal dilation D: Thrombosis with microabscesses | answer: D </s>