Imaging recommendation · Musculoskeletal

Expansile lytic bone lesion in adolescent / young adult, suspected aneurysmal bone cyst

Q: What's the alternative imaging for expansile lytic bone lesion in adolescent / young adult, suspected aneurysmal bone cyst when distinguishing from telangiectatic osteosarcoma?

MRI — MRI + biopsy (iv contrast).

Recommended: MRI affected bone (fluid-fluid levels in expansile lesion) is the preferred imaging study for expansile lytic bone lesion in adolescent / young adult, suspected aneurysmal bone cyst. Benign, blood-filled, expansile lesion.

Recommended study

MRI affected bone (fluid-fluid levels in expansile lesion)

MRI IV contrast Preferred Musculoskeletal Outpatient Reviewed 2026-05

Benign, blood-filled, expansile lesion. Primary (most) or secondary (within preexisting lesion).

If the default doesn't apply

Distinguishing from telangiectatic osteosarcoma

MRI MRI + biopsy IV contrast

Watch-outs

Telangiectatic osteosarcoma can mimic ABC

Both have fluid-fluid levels; thick enhancing nodular components and rapid growth favor malignancy.

Pearls

Fluid-fluid levels in eccentric expansile lytic lesion.
Common in metaphysis of long bones, posterior elements of spine.
Treatment: curettage + bone graft; sclerotherapy is an alternative.