All of the following organs contain aneurysm in polyaeritis nodosa except?
High-Yield Explanation
Pathophysiology in Polyaeritis nodosa The vascular lesion in polyaeritis nodosa is a necrotizing inflammation of small- and medium-sized muscular aeries. The lesions aresegmental and tend to involve bifurcations and branchings of aeries.They may spread circumferentially to involve adjacent veins. However,involvement of venules is not seen in polyaeritis nodosa and, if present, suggests microscopic polyangiitis (see below). In the acute stagesof disease, polymorphonuclear neutrophils infiltrate all layers of thevessel wall and perivascular areas, which results in intimal proliferation and degeneration of the vessel wall. Mononuclear cells infiltratethe area as the lesions progress to the subacute and chronic stages.Fibrinoid necrosis of the vessels ensues with compromise of the lumen,thrombosis, infarction of the tissues supplied by the involved vessel,and, in some cases, hemorrhage. As the lesions heal, there is collagendeposition, which may lead to fuher occlusion of the vessel lumen.Aneurysmal dilations up to 1 cm in size along the involved aeriesare characteristic of polyaeritis nodosa. Clinical features Ref - HArrisons 20e p2582