A 24-Year-Old Male Presents With an Achilles Mass | Patient Case Quiz
A 24-year-old male presents with several years of progressive bilateral growth near his achilles tendons. He complains of distal leg discomfort after working a long day in the grocery store; otherwise, this is not bothersome, except for the appearance.
His past medical history includes attention deficit disorder, irritable bowel syndrome with diarrhea since childhood, and bilateral cataracts requiring surgery at the age of 20. His diarrhea is somewhat improved with a gluten-free diet. An older sister also has diarrhea and cataracts without Achilles growth. His medications include omeprazole 20 mg daily. He denies any over-the-counter supplements or vitamins and denies tobacco, alcohol, or illicit drug use. A review of systems is remarkable for decreased concentration.
On exam, he is 67 inches tall and weighs 48 kg (BMI 16.5 kg/m2), his blood pressure is 125/78 mmHg, his heart rate is 58 bpm, and his respirations are 16/minute. He has a prominent forehead and clear lungs. He has normal S1 and S2 without murmurs, rubs, or gallops. There are no masses except for his Achilles and ankles, which are shown in Figures 1 and 2.
Which of the following is the best test to confirm the diagnosis?