What's the Diagnosis - Case 17

History 8 year old with right knee pain following minor trauma.

What’s the Diagnosis - Case 17

1

What’s the Diagnosis - Case 17

2

What’s the Diagnosis - Case 17

3

What’s the Diagnosis - Case 17

4

What’s the Diagnosis - Case 17

5

Findings Radiographs demonstrate an expansile lucency of the proximal tibial metaphysis with an eccentric positioning. MRI demonstrates multiple fluid fluid levels within the expansile lesion and periosteal thickening as well as edema. Progressive images demonstrate sclerosis or healing of the majority of the lesion but with a proximal lucency being persistent.

What’s the Diagnosis - Case 17

6

Diagnosis: Aneurysmal Bone Cyst Aneurysmal Bone Cyst, or ABC, is described histologically as an intraosseous vascular malformation with blood filled spaces. This accounts for the multiple fluid fluid levels seen on cross sectional imaging. Approximately 1/3 of ABC’s occur in the setting of another primary tumor with secondary ABC formation. Periosteal reaction does not occur typically unless there is associated trauma. Lesions are classically expansile, eccentric, and metaphyseal. Diaphyseal and epiphyseal extension does occur.

What’s the Diagnosis - Case 17

7

What’s the Diagnosis - Case 17

8

What’s the Diagnosis - Case 17

9

What’s the Diagnosis - Case 17

10

What’s the Diagnosis - Case 17

11

Resources • Resnick and Kransdorf. Bone and Joint Imaging. 3rd edition. 2005.

•

http://emedicine.medscape.com/article/386060-overview

•

http://www.bonetumor.org

Sign up for our monthly eNewsletter to find out when a new case will be posted.

What’s the Diagnosis - Case 17

12