来源：熊猫放射
病史
43岁女性，肱骨无症状病变。（A 43-year-old woman with asymptomatic lesion seen in humerus.）
影像学表现
X线片（a）及其放大后的影像（b）显示肱骨近段骨干病变（a lesion in the proximal humeral diaphysis），内见斑点状中心性钙化（containing punctuate central calcifications），内侧皮质轻度骨内膜扇贝样改变，累及范围小于骨皮质厚度的2/3（mild endosteal scalloping of the medial cortex involving <2/3 of the thickness）。未见相关的骨膜反应或骨皮质穿透（no associated periostitis or cortical breakthrough）。
CT图像（c和d）证实其为软骨性病变，内见钙化，肱骨内侧皮质轻度骨内膜扇贝样改变（confirms the presence of a chondroid lesion with punctuate calcifications and mild endosteal scalloping of the medial humeral cortex）。
鉴别诊断(前3位)
内生软骨瘤 Enchondroma
骨梗死 Bone infarct
软骨肉瘤 Chondrosarcoma
内生软骨瘤 Enchondroma
内生软骨瘤非常常见。Enchondromas are very common.
病变典型呈现分叶状，由于透明软骨的分叶状生长所致（表面积的增大可更好地利用邻近的营养物质）。Lesions typically have a lobulated appearance due to lobulated growth of hyaline cartilage (increased surface area allows better use of adjacent nutrients).
骨皮质的骨内膜贝壳样改变（在其他因素中）有助于区分内生软骨瘤和软骨肉瘤。Endosteal scalloping of the cortex (amongst other factors) can help distinguish an enchondroma from chondrosarcoma.
CT对于描述骨内膜贝壳样改变的程度非常有价值。CT is very useful in depicting the degree of endosteal scalloping.
出现其他特征，如骨膜反应、骨皮质穿透、软组织肿块、病变较大(>5cm)，应该考虑低度恶性软骨肉瘤或去分化成更高级别软骨肉瘤的可能。Other features, such as periosteal reaction, cortical breakthrough, soft tissue extension, and large lesion size (>5 cm), would raise concern for either a low grade chondrosarcoma or dedifferentiation into a higher grade chondrosarcoma.
