Age / Sex : 19 / M
Chief complaint : Left hip pain (Onset : 6 months ago) Underlying disease (-)
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Courtesy : 이규정 (Kyu-chong, Lee), 고려대학교 안암병원 (Korea university Anam Hospital) Diagnosis: Chondroblastoma
Discussion
Findings 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.
Discussion 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 MRI: 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.
References 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.
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