An oncologist is evaluating a 67-year-old male who has been receiving chemotherapy for advanced pancreatic adenocarcinoma. The patient reports a two-day history of progressive swelling and a 'heavy, aching sensation' in his right calf. He denies chest pain, shortness of breath, or recent trauma to the area. His temperature is 37.0°C (98.6°F), blood pressure is 128/82 mmHg, heart rate is 92/min, and respiratory rate is 16/min. Physical examination reveals a right lower leg that is visibly enlarged, mildly erythematous, and tender to palpation along the popliteal fossa. The right calf circumference is 5 cm greater than the left calf. Which of the following is the most appropriate initial step in evaluating this patient's symptoms?
- Lower extremity compression ultrasonographyAnswer
- BAdministration of intravenous furosemide
- CPrescription of broad-spectrum oral antibiotics
- DMeasurement of serum thyroid-stimulating hormone level
- EReassurance and instructions to elevate the leg
Answer
Lower extremity compression ultrasonography
The correct answer is lower extremity compression ultrasonography. This patient presents with classic signs of a deep vein thrombosis (DVT), including acute unilateral calf swelling, mild erythema, and tenderness. His active pancreatic cancer and ongoing chemotherapy place him in a severely hypercoagulable state (Trousseau syndrome). In patients with a high pretest probability for DVT (e.g., Modified Wells score ≥ 2), the most appropriate initial diagnostic test is a venous duplex ultrasound (compression ultrasonography) to visualize the deep veins and check for lack of compressibility, which indicates a clot. D-dimer testing is not appropriate here as it is only useful for ruling out DVT in low-probability patients; it would almost certainly be elevated in a patient with metastatic cancer regardless of a clot's presence.
Step-by-Step Solution
Key Concept
Diagnosis of deep vein thrombosis in a hypercoagulable oncology patient.