Age / Sex : 13 / M

Age / Sex : 13/M

Chief complaint : left knee pain

1) What is your impression?



Two weeks later, you can see the final diagnosis with a brief discussion of
this case.



* Send Application Answers to In Sook Lee, MD ([email protected])



Courtesy : Hee Jin Park, Kangbuk Samsung hospital

Juxtacortical chondroma

Discussion

Findings:

:consists of small surface mass ( < 3 cm) & appears
as radiolucent

:oval or oblong defect on periphery of underlying cortex

:The lesion is underlined by a thin, distinct cortical reaction, radiating from
the cortex, providing a "sunburst" appearance 

:occassionally intralesional calcifications & minimal periosteal     

     reaction

Differential Diagnosis: Fibrous cortical defect, cortical
desmoid, aneurysmal bone cyst, periosteal chondrosarcoma, periosteal
osteosarcoma

Diagnosis:
Juxtacortical chondroma

Discussion: 1. Cartilaginous tumor that arises from surface
of cortex deep to the periosteum producing broad based cartilaginous mass

2. often after adolescence

3. Not infiltrate the adjacent soft tissue

4. Location:

 - >50%: lateral
cortex of proximal humerus

 - other long bones

References:

1.     Resnick D, Kyriakos M, Greenway GD.
Tumors and tumor-like

lesions of
bone: imaging and pathology of specific lesions. In:

Resnick D,
ed. Diagnosis of Bone and Joint Disorders. 3rd ed.

Philadelphia:
Saunders, 1995:3707–11.

2.  Lewis MM, Kenan S, Yabut SM, et al.
Periosteal chondroma. A

report of 10
cases and review of the literature. Clin Orthop 1990;

256:185–92.

3.  Boriani S, Bacchini P, Bertoni F, et al.
Periosteal chondroma. A