Weekly Case

Title : Case 854

Age / Sex : 19 / M

Chief complaint : Left hip pain (Onset : 6 months ago)
Underlying disease (-)

What is your diagnosis?

Two weeks later, you can see the final diagonosis with a brief discussion of this case (Please submit only one answer)

Courtesy : 이규정 (Kyu-chong, Lee), 고려대학교 안암병원 (Korea university Anam Hospital)




Clinical information: young male.
X-ray & CT: About 3.9cm sized geographic osteolytic tumor in left femur greater trochanter, apophysis.
MRI: About 3.9 x 3.8 x 3.0 cm sized well-defined lobulating contoured heterogeneous T2 high, enhancing solid tumor in left femur greater trochanter, involving apophysis.
- Combined extensive bone marrow edema.
- Focal periosteal T2 high signal change with enhancement around tumor: DDx. pathologic fracture.

Chondroblastoma: Benign cartilage tumor arising in epiphysis of skeletally immature individuals
Epidemiology: M > F (2:1), commonly affects those 10-25 years old
Location: >75% long bone, epiphysis or apophysis
Imaging findings:
Radiography and CT:
Well-defined, geographic osteolytic lesion
Eccentrically or centrally location in epiphysis
Thin sclerotic rim (smooth > scalloped > lobulated)
Calcific foci within the lesion (30~50%)
Mild cortical expansion or thinning may occur
Inhomogeneously low signal on T1, variable SI on T2 (due to chondroid matrix, calcification, and fluid within lesion)
Surrounding bone marrow edema + adjacent soft tissue signal change
Possible interval fluid-fluid levels -> due to ABC change.

Angelini A, et al. Chondroblastoma of the Foot: 40 Cases from a Single Institution. J Foot Ankle Surg 2018;57:1105-1109.
Chai JW, et al. A Chondroblastoma Versus a Giant Cell Tumor: Emphasis on the MR Imaging Features. J Korean Radiol Soc 2007;57:371-375.

Correct Answer
Total applicants 27 Correct answers 5
Name Institution
김도우 공중보건의사, 전문의
김재민 원주연세병원, 전문의
김신영 전공의
전차웅 가톨릭대학교 여의도성모병원, 전공의
김성진 전문의
Semi-Correct Answer
Total applicants 27 Semi-Correct answers 9
이진영 전문의
박소연 일산백병원, 전공의
김승관 전문의
주황선 차의과학대학교 분당차병원, 전공의
오지수 전문의
이혜란 전문의
강지희 전문의
박호영 전문의
김지환 전문의