Aneurysmal bone cyst (ABC)

Aris Musabji, M.D.

Christine Carqueville

Daniel Schwartz, M.D.

Children's Memorial Hospital


10 year old male with neck pain


Aneurysmal bone cyst, lesion, ABC, cervical spine, plain film, CT, MRI, 1083

Publication Date: 2005-12-13


10 year old male with neck pain


Lateral C-spine radiograph (image 1) shows an expansile lucent lesion involving the posterior elements of the C2 vertebral body.

CT (images 2-4): Expansile lytic lesion replacing the spinous process and left and right lamina of C2. Lesion is noted to extend into the posterior paraspinous soft tissues. Post-contrast images (images 3-4) suggest a multiloculated component to the lesion with fluid-fluid levels.

MRI (images 5-10): Heterogeneous mass involving C2 lamina and spinous process which contains multiple locules with fluid-fluid levels. No definite spinal cord involvement. Mild narrowing of the spinal canal due to anterior subluxation of C2 over C3.


Aneurysmal bone cyst (ABC) of C2


Aneurysmal bone cysts (ABC) are classified as "a pathopysiologic change rather than a unique entity". They are complex lesions often discovered between the first and third decades of life and can appear in the craniofacial bones, the vertebral column, or the metaphyses of the bones of the lower extremities. An ABC can fall into either a primary or secondary category. Precursors to secondary ABC include giant cell tumor, chondroblastoma, osteoblastoma, nonossifying fibroma, fibrous dysplasia, solitary bone cyst, hemangioma, osteosarcoma and fibrous histocytoma.

Radiographical findings of ABC show lucent, eccentric, expansile, "blowout" lesions with smooth, thin, bony walls that may or may not produce periosteal reaction. On CT or MRI imaging, a charateristic feature is the appearance of fluid-fluid levels formed by sedimentation of degraded blood products.


  1. Kuhn, J.P., Slovis, T.L., Haller, J.O., CAFFEY'S PEDATRIC DIAGNOSTIC IMAGING, Elsevier, Inc., 2004, 2381.

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