In primary hyperparathyroidism, which radiographic bone changes are classic?

• A. Subperiosteal bone resorption and brown tumors
• B. Osteoporosis without resorption
• C. Osteophyte formation
• D. Widening of growth plates

Answer: (A)

In primary hyperparathyroidism, excess parathyroid hormone drives osteoclast-mediated bone resorption, leading to distinctive radiographic changes. The classic pattern includes subperiosteal bone resorption, most evident on the radial aspects of the middle phalanges, and brown tumors (osteitis fibrosa cystica) as focal, lytic bone lesions from accelerated turnover. Together, these findings strongly point to this condition on imaging. Generalized bone loss can occur, but the combination of subperiosteal erosions and brown tumors is what makes the radiographic picture classic. Other options don’t fit as well: osteoporosis without resorption lacks the characteristic subperiosteal changes; osteophytes arise from degenerative joint disease; widening of growth plates is seen in rickets or scurvy rather than primary hyperparathyroidism.