A 45-year-old woman comes to the office due to 3 days of progressive pain in the right upper quadrant, nausea, and vomiting. In the preceding year, the patient has had fatigue, weight loss, joint pain, and intermittent abdominal pain. Laboratory studies show increased blood urea nitrogen and serum creatinine. Right-upper quadrant ultrasound shows no evidence of gallstones, but an inflamed gallbladder is present. The patient undergoes cholecystectomy, and subsequent biopsy of the submucosal gallbladder vessels is shown in the exhibit (2 images). Which of the following is the most likely diagnosis?

Question

A 45-year-old woman comes to the office due to 3 days of progressive pain in the right upper quadrant, nausea, and vomiting.  In the preceding year, the patient has had fatigue, weight loss, joint pain, and intermittent abdominal pain.  Laboratory studies show increased blood urea nitrogen and serum creatinine.  Right-upper quadrant ultrasound shows no evidence of gallstones, but an inflamed gallbladder is present.  The patient undergoes cholecystectomy, and subsequent biopsy of the submucosal gallbladder vessels is shown in the exhibit (2 images).  Which of the following is the most likely diagnosis?

Quizplus · Accepted Answer

11ec160b_38e1_66b2_9249_99a2f00107af_MD0001_00 This patient's vomiting, right upper quadrant pain, and gallbladder inflammation with no evidence of gallstones indicates acute acalculous cholecystitis. Although a variety of conditions cause acute acalculous cholecystitis, the presence of long-standing, nonspecific symptoms (eg, fatigue, weight loss, arthralgias) and biopsy findings of fibrinoid necrosis of the submucosal arteries of the gallbladder raise strong suspicion for polyarteritis nodosa (PAN). PAN is a systemic vasculitis of medium-sized muscular arteries; biopsy of affected areas generally reveals the following: In contrast to many other vasculitides (eg, granulomatosis with polyangiitis), there is no granulomatous inflammation in PAN. PAN typically attacks arteries of the kidneys (eg, increased BUN/creatinine), skin, neurologic system, and gastrointestinal tract; most cases present due to symptoms of tissue ischemia from artery lumen narrowing/thrombosis or bleeding from microaneurysm rupture. In this case, damage to the submucosal gallbladder arteries likely caused gallbladder ischemia, which lead to acalculous cholecystitis. Other common gastrointestinal findings in PAN include bead-like microaneurysm formation in the mesenteric vessels, mesenteric ischemia, and bowel necrosis/rupture. (Choice A) Angiodysplasia is thought to arise from intermittent obstruction of submucosal veins at the muscularis propria of the gastrointestinal tract. Biopsy shows dilated small vessels lined by thin-walled endothelium; infiltration with inflammatory cells would not be seen. In addition, patients with angiodysplasia generally have gastrointestinal bleeding, not acalculous cholecystitis. (Choice B) Antiphospholipid-antibody syndrome is characterized by small-vessel thrombosis due to the formation of autoantibodies against phospholipid-binding proteins. It is often triggered by underlying systemic lupus erythematosus, which can cause long-standing nonspecific symptoms. However, acute biopsy would show thrombosed vessels, not vessels with fibrinoid necrosis and neutrophilic inflammation. (Choice C) Granulomatosis with polyangiitis is an antineutrophil cytoplasmic antibody-positive vasculitis that generally affects the upper airways, lungs, and kidneys. Gastrointestinal involvement is uncommon. (Choice E) Thromboangiitis obliterans primarily attacks vessels in the extremities. It is marked by inflammatory thrombi with relative sparing of the vessel wall and intact internal elastic lamina. Fibrinoid necrosis would not be seen. Most cases are seen in young smokers. Educational objective: Polyarteritis nodosa is characterized by segmental, transmural, necrotizing inflammation of medium-sized muscular arteries. Manifestations arise due to tissue ischemia from arterial lumen narrowing/thrombosis or bleeding from microaneurysms. The vessels of the kidneys, skin, peripheral nerves, and gastrointestinal tract are affected most commonly; the lung is typically spared.

A 45-Year-Old Woman Comes to the Office Due to 3