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Age / Sex : 16 / M
Age / Sex: 16 / M
Chief complaint: Right shoulder 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 (lis@pusan.ac.kr)
Courtesy :
Chang Ho Kang, Korea University Anam Hospital
Diagnosis: Chondroblastoma with secondary aneurysmal bone cyst
Discussion
Findings:
Plain
radiograph shows well-defined osteolytic lesion involving the glenoid, neck,
and coracoid process of the scapula.
MRI shows
fluid-fluid levels in the lobulated tumor. Extraosseous extension through
suprascapular notch is evident.
Differential Diagnosis:
Osteosarcoma,
clear cell chondrosarcoma, chondromyxoid fibroma, osteoblastoma, eosinophilic
granuloma
Diagnosis:
Chondroblastoma
with secondary aneurysmal bone cyst
Discussion:
Chondroblastoma
is rare, accounting for approximately 1% of all benign bone tumors. Most cases
occur during the 2nd decade of life. The presenting symptoms are mild pain and,
less often, local swelling. The long bones are the most common location for
chondroblastoma, although the relative incidence in individual bones is
debated. The pelvic bones are the most frequently involved flat bones, followed
by the calcaneus. Occasional scapular lesions have been reported.
Expansion of
the bone with varying amounts of stippled calcifications is typical of
chondroblastoma. Lesion typically involves the physeal plate, adjacent
epiphysis, and metaphysis. Lesions often have fine lobular margins and typically
have low-intermediate heterogeneous signal on T1WI and mixed low, intermediate,
and/or high signal on T2WI. Areas of low signal on T2WI are secondary to
chondroid matrix mineralization, and/or hemosiderin. Lesions can show margin or
septal Gd-contrast enhancement patterns. The cortical breach and extraosseous
portion observed on MRI in our case was worrisome. In chondroblastoma, cortical
disruption and extraosseous extension are uncommon.
References:
Bloem JL, Mulder JD. Chondroblastoma: a
clinical and radiological study of 104 cases. Skeletal Radiol. 1985;14(1):1-9.
Resendes M, Parker BR, Kempson RL, Jones HH, Nagel DA. Case
report 663. Unusual chondroblastoma of the scapula. Skeletal Radiol. 1991;20(3):222-5.
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