Nosrat Cameron, Sweetwood Kevin, Motamedi Daria
Department of Radiology, University of California, 513 Parnassus Ave, Room S257, Box 0628, San Francisco, CA 94143, USA.
Radiol Case Rep. 2025 Sep 15;20(12):5974-5976. doi: 10.1016/j.radcr.2025.08.083. eCollection 2025 Dec.
Parosteal lipomas are a rare benign fat-containing neoplasm that originates from mature adipose tissue near the bone periosteum that can often be difficult to differentiate from malignant tumors. We present the case of a 75-year-old female presenting with several months of a growing, uncomfortable right shoulder mass without neurological or motor deficits. Computerized tomography (CT) demonstrated a well-defined mass located deep to the deltoid along the proximal humerus with peripheral fat attenuation while follow-up magnetic resonance imaging (MRI) demonstrated internal central enhancement and thin fibrous septae. Such findings were most consistent with a parosteal lipoma, and given the indolent nature of the mass, absence of aggressive features, and stable size over a 5-month period, conservative management with observation and interval imaging was recommended. This case emphasizes that while histological confirmation remains the gold standard, magnetic resonance imaging (MRI) is currently the most valuable tool in differentiating parosteal lipoma from atypical lipomatous tumors and other fat-containing lesions and guiding management decisions.
骨旁脂肪瘤是一种罕见的含脂肪良性肿瘤，起源于骨骨膜附近的成熟脂肪组织，常难以与恶性肿瘤相鉴别。我们报告一例75岁女性患者，其右肩部肿物逐渐增大且不适已有数月，无神经或运动功能缺损。计算机断层扫描（CT）显示沿肱骨近端三角肌深层有一界限清楚的肿物，其外周呈脂肪密度，而后续的磁共振成像（MRI）显示内部中央强化及薄纤维间隔。这些表现最符合骨旁脂肪瘤，鉴于肿物生长缓慢、无侵袭性特征且在5个月内大小稳定，建议采用观察及定期成像的保守治疗方法。该病例强调，虽然组织学确诊仍是金标准，但磁共振成像（MRI）目前是鉴别骨旁脂肪瘤与非典型脂肪瘤性肿瘤及其他含脂肪病变并指导治疗决策的最有价值工具。
