Takenaga Ryan K, Frassica Frank J, McCarthy Edward F
Johns Hopkins University School of Medicine, Baltimore, MD, USA.
Iowa Orthop J. 2007;27:104-7.
Chondromyxoid fibroma is a rare cartilage tumor that represents less than 1% of all bone tumors. When in a long bone, it is usually an intramedullary lesion that is eccentrically located in the metaphyseal region. Chondromyxoid fibroma may also have unusual presentations. These include intracortical lesions and subperiosteal lesions. There have been 14 reported cases of intracortical chondromyxoid fibroma, but there have been only four reports of subperiosteal lesions. A subperiosteal location, therefore, is extremely rare for a chondromyxoid fibroma. We present two new cases of subperiosteal chondromyxoid fibroma. Given its rarity, chondromyxoid fibroma is often not in the differential diagnosis of a painful, subperiosteal scalloped lesion in a long bone. Other entities such as periosteal chondroma, periosteal myxoma, subperiosteal ganglion cyst, or subperiosteal osteoid osteoma are more likely to be considered. Our cases illustrates that subperiosteal chondromyxoid fibroma, although rare, should be included in the differential diagnosis of a painful, radiographically inactive lytic lesion on the surface of a long bone.
软骨黏液样纤维瘤是一种罕见的软骨肿瘤，占所有骨肿瘤的比例不到1%。位于长骨时，它通常是一种位于干骺端区域偏心的髓内病变。软骨黏液样纤维瘤也可能有不寻常的表现，包括皮质内病变和骨膜下病变。据报道，皮质内软骨黏液样纤维瘤有14例，但骨膜下病变仅有4例报道。因此，骨膜下位置对于软骨黏液样纤维瘤来说极为罕见。我们报告两例骨膜下软骨黏液样纤维瘤的新病例。鉴于其罕见性，软骨黏液样纤维瘤在长骨疼痛性骨膜下扇贝样病变的鉴别诊断中常不被考虑。其他病变如骨膜软骨瘤、骨膜黏液瘤、骨膜下腱鞘囊肿或骨膜下骨样骨瘤更有可能被考虑。我们的病例表明，骨膜下软骨黏液样纤维瘤虽然罕见，但在长骨表面疼痛性、影像学无活性的溶骨性病变的鉴别诊断中应予以考虑。
