检查骨膜下脂肪瘤的多模式成像特征。经IRB批准，我们回顾了1990-2020年机构影像数据库和病历，包括经病理证实和/或成像诊断的骨膜下脂肪瘤。共有22例患者（男性12例，女性10例），平均年龄为57.1±12.7岁（范围31-80岁）。11/22例（50%）经病理活检或手术切除证实，11/22例（50%）具有符合骨膜下脂肪瘤成像特征。病变最常发生于股骨（8/22，36%），其次是前臂（3/22，14%）。所有病例均显示出一种紧贴皮质表面的骨膜下脂肪肿块，其中包含一个骨性突起。骨性突起在16/22例（73%）中被描述为有茎的，6/22例（27%）中为无茎的。骨性突起的平均最大尺寸为2.4±1.6cm（范围0.8-6.1cm），脂肪部分为7.8±3.8cm（范围2.0-19.5cm）。在22例中，12例（55%）的骨性突起中含有成熟骨，10例（45%）含有成熟骨和辐射骨刺的混合物。在肿块的脂肪部分中有非脂肪成分的病例有13/22例（59%）。大多数病例（19/22，85%）在骨性突起基部附近具有皮质增厚/骨膜炎。两名患者进行了骨扫描，显示骨性突起有摄取，两名患者进行了FDG PET/CT检查，没有摄取。骨膜下脂肪瘤是一种罕见的良性肿瘤，具有诊断性的多模式成像特征，可能避免了活检的需要。© 2023. 版权所有，由国际骨科协会（ISS）独家许可。

To examine the multimodality imaging characteristics of parosteal lipomas.With IRB approval, our institutional imaging database and medical record were retrospectively reviewed from 1990-2020 for cases of pathologically-proven and/or imaging diagnosed parosteal lipomas.There were 22 patients (12 males, 10 females) with a mean age of 57.1 ± 12.7 years (range 31-80 years). 11/22 cases (50%) were pathologically-confirmed on biopsy or surgical resection and 11/22 (50%) had imaging features compatible with parosteal lipoma. Lesions occurred most commonly along the femur (8/22, 36%), followed by the forearm (3/22, 14%). All cases demonstrated a juxtacortical fatty mass containing an osseous excrescence that was firmly attached to the cortical surface. The osseous excrescences were characterized as pedunculated in 16/22 (73%) and sessile in 6/22 (27%). The average largest dimension of the osseus excrescences was 2.4 ± 1.6 cm (range 0.8-6.1 cm) and the lipomatous portions 7.8 ± 3.8 cm (range 2.0-19.5 cm). The excrescences contained mature bone in 12/22 (55%) cases and a mixture of mature bone and radiating bone spicules in 10/22 (45%). There were non-lipomatous elements in the fatty portion of the mass in 13/22 (59%) of cases. Most cases (19/22, 85%) had cortical thickening/periostitis near the base of the osseous stalk. Two patients had a bone scan that demonstrated uptake in the osseous excrescence, and two patients had an FDG PET/CT that demonstrated no uptake.Parosteal lipomas are a rare benign lipomatous tumor with pathognomonic multimodality imaging features that may obviate the need for biopsy.© 2023. The Author(s), under exclusive licence to International Skeletal Society (ISS).