A physician-validated, board-style question from the Active Transport QBank. Try it, then check the reasoning for every option.
A 50-year-old man comes to the physician for the evaluation of recurrent episodes of chest pain, difficulty breathing, and rapid heart beating over the past two months. During this period, he has had a 4-kg (8.8-lb) weight loss, malaise, pain in both knees, and diffuse muscle pain. Five years ago, he was diagnosed with chronic hepatitis B infection and was started on tenofovir. His temperature is 38°C (100.4°F), pulse is 110/min, and blood pressure is 150/90 mm Hg. Cardiopulmonary examination shows no abnormalities except for tachycardia. There are several ulcerations around the ankle and calves bilaterally. Laboratory studies show:
Hemoglobin 11 g/dL
Leukocyte count 14,000/mm3
Erythrocyte sedimentation rate 80 mm/h
Serum
Perinuclear anti-neutrophil cytoplasmic antibodies negative
Hepatitis B surface antigen positive
Urine
Protein +2
RBC 6-7/hpf
Which of the following is the most likely diagnosis?"
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A
Takayasu arteritisIncorrect. Takayasu arteritis is a large-vessel vasculitis in young Asian women causing diminished pulses ("pulseless disease"), not multisystem with skin ulcers and HBV.
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B
Giant cell arteritisIncorrect. Giant cell arteritis affects elderly (>50) with temporal headache, jaw claudication, and vision loss; doesn't cause skin ulcers or kidney involvement, and isn't HBV-associated.
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C
Polyarteritis nodosaCorrect. PAN is a medium-vessel vasculitis associated with HBV (30% of cases), characterized by constitutional symptoms, hypertension, skin ulcerations, renal involvement (microaneurysms), and ANCA-negative serology.
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D
Granulomatosis with polyangiitisIncorrect. GPA is ANCA-positive (c-ANCA/PR3); the negative ANCA here makes GPA unlikely. GPA also typically involves upper airways and lungs — not described.
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E
Microscopic polyangiitisIncorrect. Microscopic polyangiitis is a small-vessel ANCA-associated vasculitis (typically p-ANCA/MPO positive) causing pulmonary-renal syndrome; this patient's negative ANCA and HBV-associated medium-vessel involvement favor polyarteritis nodosa instead.
↑ Tap an answer to reveal the reasoning
Answer: C. This man has a multisystem vasculitis: constitutional symptoms (fever, weight loss, malaise, myalgias, arthralgias), hypertension, skin involvement (lower-extremity ulcerations), and renal involvement (proteinuria, hematuria) — all in the setting of chronic hepatitis B infection. ANCA is negative. This combination is essentially diagnostic of polyarteritis nodosa (PAN).
PAN is a medium-vessel necrotizing vasculitis associated with hepatitis B in about 30% of cases. It typically spares the lungs (no pulmonary involvement here, unlike GPA/EGPA) and the glomerulus (renal involvement is from renal artery branch vasculitis with microaneurysms, causing hypertension and ischemic glomerular injury, not pauci-immune glomerulonephritis). The classic angiographic finding is multiple microaneurysms in mesenteric and renal arteries.
Granulomatosis with polyangiitis (GPA) is ANCA-positive (c-ANCA/PR3), affects the upper airway (saddle nose, sinusitis) and lungs, and causes a pauci-immune glomerulonephritis — the negative ANCA argues against it. Takayasu arteritis is a large-vessel vasculitis affecting young women, causing pulseless extremities. Giant cell arteritis affects patients >50 with headache, jaw claudication, and vision loss — not multisystem with HBV.
**Why each option:**
**A.** Takayasu arteritis is a large-vessel vasculitis in young Asian women causing diminished pulses ("pulseless disease"), not multisystem with skin ulcers and HBV.
**B.** Giant cell arteritis affects elderly (>50) with temporal headache, jaw claudication, and vision loss; doesn't cause skin ulcers or kidney involvement, and isn't HBV-associated.
**C.** Correct. PAN is a medium-vessel vasculitis associated with HBV (30% of cases), characterized by constitutional symptoms, hypertension, skin ulcerations, renal involvement (microaneurysms), and ANCA-negative serology.
**D.** GPA is ANCA-positive (c-ANCA/PR3); the negative ANCA here makes GPA unlikely. GPA also typically involves upper airways and lungs — not described.