A physician-validated, board-style question from the Active Transport QBank. Try it, then check the reasoning for every option.
A 56-year-old man comes to the emergency department because of pain and swelling in his left leg. He has a history of pancreatic cancer and is currently receiving chemotherapy. Three weeks ago, he had a similar episode in his right arm that resolved without treatment. His temperature is 38.2°C (100.8°F). Palpation of the left leg shows a tender, cord-shaped structure medial to the medial condyle of the femur. The overlying skin is erythematous. Which of the following vessels is most likely affected?
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A
Anterior tibial arteryIncorrect. the anterior tibial artery lies on the anterolateral lower leg, not medial to the femoral condyle.
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B
Superficial femoral arteryIncorrect. the superficial femoral artery is deep in the femoral triangle and adductor canal, pulsatile, not palpable as a tender superficial cord.
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C
Great saphenous veinCorrect. the great saphenous vein runs superficially along the medial leg and thigh, just posterior to the medial femoral condyle; superficial thrombophlebitis here is classic for Trousseau syndrome in pancreatic cancer.
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D
External iliac veinIncorrect. the external iliac vein is deep in the pelvis and not palpable from the surface.
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E
Popliteal veinIncorrect. The popliteal vein lies deep in the posterior knee and is not palpable as a superficial cord; superficial thrombophlebitis in Trousseau syndrome characteristically affects the great saphenous vein along the medial leg.
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Answer: C. A cancer patient (pancreatic adenocarcinoma) with migratory episodes of superficial thrombophlebitis — a tender, palpable, cord-like vein with overlying erythema, first in the right arm and now in the medial thigh — has Trousseau syndrome (migratory superficial thrombophlebitis associated with visceral malignancy, most classically pancreatic, gastric, or lung).
The affected vessel here is identified anatomically: a tender cord-shaped structure medial to the medial femoral condyle. The great saphenous vein runs along the medial aspect of the lower extremity, passing about a hand's breadth posterior to the medial border of the patella and just behind the medial femoral condyle before ascending the thigh. It is the longest superficial vein in the body and the most common site of superficial thrombophlebitis.
The anterior tibial artery is on the anterolateral lower leg. The superficial femoral artery is deep and pulsatile, not palpable as a tender cord. The external iliac vein is deep in the pelvis, not palpable. The clinical clue of cancer-associated migratory thrombophlebitis is Trousseau, and the anatomic clue of medial thigh/medial knee is the great saphenous vein.
**Why each option:**
**A.** Incorrect — the anterior tibial artery lies on the anterolateral lower leg, not medial to the femoral condyle.
**B.** Incorrect — the superficial femoral artery is deep in the femoral triangle and adductor canal, pulsatile, not palpable as a tender superficial cord.
**C.** Correct — the great saphenous vein runs superficially along the medial leg and thigh, just posterior to the medial femoral condyle; superficial thrombophlebitis here is classic for Trousseau syndrome in pancreatic cancer.
**D.** Incorrect — the external iliac vein is deep in the pelvis and not palpable from the surface.