USMLE Step 2 CK High-Yield Practice Test

In the context of a 60-year-old man presenting with bone pain and the suspicion of multiple myeloma, the finding of punched-out lesions on X-ray is indicative of this condition. Multiple myeloma is a hematological malignancy characterized by the proliferation of monoclonal plasma cells in the bone marrow. As these malignant plasma cells expand, they can cause localized bone destruction, leading to the classic "punched-out" appearance seen on imaging studies.

These lesions occur in various locations, particularly in flat bones such as the skull, vertebrae, ribs, and pelvis. The underlying mechanism involves the disruption of normal bone remodeling, with the overproduction of osteoclast-activating factors by the neoplastic plasma cells, resulting in increased bone resorption. This is a hallmark feature that distinguishes multiple myeloma from other conditions that might also present with bone pain.

Other laboratory findings associated with multiple myeloma may include elevated serum protein (often with a monoclonal spike), renal impairment, and anemia, but the unique radiological finding of punched-out lesions is a well-recognized key feature.

In summary, the presence of punched-out lesions on X-ray is a classic finding in multiple myeloma and correlates with the