USMLE® Step 1 style questions USMLE
A 19-year old man comes to the office because of a progressive, painless mass over his right knee. His medical history is noncontributory, the patient denies a history of trauma, fever, or any other disease. When asking the patient about alleviating and exacerbating factors, he mentions that the pain is very intense whenever he decides to go exercise. Physical exam shows, a hard, immobile, and painless palpable mass, in addition to, muscle atrophy, and a limited range of motion of his right knee. His temperature is 36.1°C (96.9°F), pulse is 94/min, respirations are 19/min, and blood pressure is 110/80 mmHg. A conventional knee radiograph is obtained and shown below.
This patient most likely has which of the following conditions?