USMLE® Step 1 style questions USMLE
A 45-year-old man comes to the clinic due to right shoulder pain for the past 2 months. He works as a carpenter and initially thought it was work-related. However, it has recently become more severe and often awakens him at night. The patient describes the pain as dull, deep, and 4/10 in intensity. Medical history is remarkable for diabetes mellitus type 2 manages with metformin. The patient smoked 1 pack of cigarettes per day for 20 years, but quit 5 years ago. Vital signs are within normal limits. On physical examination, he has difficulty with shoulder movement due to pain. Passive range of motion is full but produces the pain as well. X-ray of shoulder shows a mixed radiolucent and sclerotic lesion with a ring-and-arc pattern of calcifications. The cortex appears thickened, but a periosteal reaction is scant. Which of the following is the most likely diagnosis?
Chondrosarcoma is a malignant tumor that originates in the mesenchymal cells of (cells that produce) cartilage. Chondrosarcoma most commonly affects the medullary cavity of the pelvis, proximal humerus, and femur. Symptoms of chondrosarcoma include pain, swelling, weight loss, and pathological fractures. Chondrosarcoma is diagnosed through physical examination, imaging tests (such as X-rays, MRI scans, or CT scans), and tissue biopsy.