An 11-year-old boy presents with back pain. Radiograph shows an expansile lytic lesion involving the posterior elements of a lumbar vertebra. MRI demonstrates multiple fluid-fluid levels within the lesion. What is the most likely diagnosis?

• A Aneurysmal bone cyst ✓
• B Telangiectatic osteosarcoma
• C Vertebral haemangioma
• D Osteoid osteoma

Explanation

Primary aneurysmal bone cyst is a benign expansile lesion of childhood that characteristically involves the posterior elements of the spine and shows blood-filled cavernous spaces separated by fibrous septa. On MRI these produce multiple fluid-fluid levels due to layering of blood products, which is its hallmark. Vertebral haemangiomas are central in the body with a polka dot pattern, and osteoid osteoma produces intense pain with a small nidus.

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.