A 13-year-old boy has chronic hip pain. X-ray shows a lytic lesion in the proximal femoral metaphysis with a ground-glass matrix and endosteal scalloping, with varus bowing of the femoral neck. He also has cafe-au-lait macules with irregular borders and documented precocious puberty. The most likely diagnosis is:

• A Hereditary multiple osteochondromas
• B Ollier disease
• C McCune-Albright syndrome ✓
• D Paget disease of bone

Explanation

Polyostotic fibrous dysplasia combined with cafe-au-lait macules (classically described as coast of Maine with irregular margins) and endocrine hyperfunction such as precocious puberty defines McCune-Albright syndrome, caused by a postzygotic activating GNAS mutation. The ground-glass matrix and shepherd's crook deformity of the proximal femur are characteristic radiological features of fibrous dysplasia. Ollier disease denotes multiple enchondromas without these extraskeletal features.

Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.