Screening for Occult Malignancy in Unprovoked Venous Thromboembolism

A 57-year-old woman presents to the emergency department after two days of pain and swelling in her left thigh. She denies any recent surgery, infection, hospitalization, or prolonged immobilization. She denies any recent trauma to her left lower extremity. She has no personal history of malignancy. She takes no medications. She has no family history of deep venous thrombosis (DVT) or pulmonary embolism (PE), and no family history of malignancy. She is up to date with screening colonoscopy, having had a normal study within the last year, and is up to date with cervical cancer screening, having had a pap smear within the last two years that revealed no intraepithelial lesion. She has not had a mammogram in three years.

On exam, she is afebrile, with a heart rate of 72 beats per minute, a blood pressure of 120/70 mm Hg, a respiratory rate of 16 bpm, and an oxygen saturation of 98% on room air. Her jugular venous pressure is seen at 7 cm H20. Cardiac auscultation reveals a regular rate and rhythm with a normal S1 and S2. Her lower extremities are notable for erythema in the left lower extremity, as well as pitting edema. On measurement, her left calf diameter is 3 cm greater than her right calf diameter.

Initial laboratory testing is notable for a creatinine of 0.65, a white blood cell count of 7,300, a hematocrit of 39%, a platelet count of 239,000, an international normalized ratio (INR) of 1.0, and a partial thromboplastin time of 29 seconds. A D-dimer test is deferred. Compression venous ultrasonography reveals absence of compressibility in the left femoral vein, consistent with DVT. The patient is diagnosed with unprovoked proximal DVT.

The patient is prescribed apixaban 10 mg twice daily for seven days, followed by 5 mg twice daily. Her pain subsides over the following two days.

Which of the following is the appropriate cancer screening in this patient?

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