A 55-year-old man is admitted to the hospital due to abdominal discomfort . Medical history includes asthma and hypertriglyceridemia, for which the patient takes the appropriate medications. He has smoked a pack of cigarettes daily for 30 years and used intravenous drugs in the past. The patient is treated empirically with a proton pump inhibitor; upper gastrointestinal endoscopy does not reveal a source for the pain. An abdominal CT angioghraphy shows numerous small aneurysms and stenosis of renal artery. Microscopic examination of the vessel walls shows diffuse inflammation of the adventitia and marked thickening of the inner layers due to proliferation of loose connective tissue; the arterial lumen is significantly narrowed. Which of the following is the most likely diagnosis?

Question

A 55-year-old man is admitted to the hospital due to abdominal discomfort .  Medical history includes asthma and hypertriglyceridemia, for which the patient takes the appropriate medications.  He has smoked a pack of cigarettes daily for 30 years and used intravenous drugs in the past.  The patient is treated empirically with a proton pump inhibitor; upper gastrointestinal endoscopy does not reveal a source for the pain. An abdominal CT angioghraphy shows numerous small aneurysms and stenosis of renal artery. Microscopic examination of the vessel walls shows diffuse inflammation of the adventitia and marked thickening of the inner layers due to proliferation of loose connective tissue; the arterial lumen is significantly narrowed.  Which of the following is the most likely diagnosis?

Quizplus · Accepted Answer

Eductional Objective: Polyarteritis nodosa is a systemic vasculitis of medium-sized muscular arteries marked by segmental, transmural, arterial wall inflammation with fibrinoid necrosis.  This narrows the arterial lumen and increases risk of thrombosis and tissue ischemia/infarction.  Damage to the internal and external elastic laminae also increases the risk of microaneurysm.  Tissue damage primarily occurs in the kidneys, gastrointestinal tract, neurologic system, and skin; the lungs are usually spared.

A 55-Year-Old Man Is Admitted to the Hospital Due to Abdominal