MRI of a 15-year-old girl with a painful expansile lesion of the posterior elements of a lumbar vertebra shows multiple locules containing fluid-fluid levels with variable signal intensities, surrounded by a thin enhancing rim. The most likely diagnosis is:

• A Aneurysmal bone cyst ✓
• B Simple bone cyst
• C Giant cell tumour
• D Telangiectatic osteosarcoma

Explanation

Multiple fluid-fluid levels within expansile multiloculated cavities on MRI are the hallmark of aneurysmal bone cyst, reflecting layering of blood products of differing ages within cavernous spaces. While telangiectatic osteosarcoma can also show fluid-fluid levels, it shows an aggressive matrix, cortical destruction and a soft tissue mass, which are absent in this description of a benign expansile lesion.

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.