Previgliano Carlos Humberto, Sangster Guillermo Pablo, Simoncini Alberto Andrés, Carbó Alberto Ivo, González Enrique, Li Benjamin, D'Agostino Horacio
Department of Radiology, Louisiana State University Health Sciences Center, Shreveport, USA.
J La State Med Soc. 2010 Jan-Feb;162(1):40-3.
Parosteal lipomas (PL) account for 0.3% of all lipomas. They are composed of adipose tissue adjacent to the bone cortex and elicit bony reactive changes. Location of this typically slow-growing indolent lesion in the ribs is unusual. Albeit a benign condition, PL imaging findings may be misinterpreted as a malignant lesion. We present a patient with a PL in which a surgical biopsy was performed. Distinctive features of PL in the computed tomographic (CT) scan and magnetic resonance image (MRI) are described. Familiarity with the characteristic radiographic PL signs assist in avoiding invasive diagnostic studies. Lipomas are benign tumors consisting of mature fat cells. They are the most common mesenchymal neoplasias and account for 50% of all soft tissue tumors. Their location varies from superficial to deep seated lesions. Musculoskeletal lipomatous lesions may be located in bones, soft tissues, and may also affect joint and tendon sheaths. PL is a rare benign deep fatty-tissue tumor that arises contiguous to the periosteum without originating from it. In 1836, Seering was the first in describing this lesion and named it "periosteal lipoma." Upon realization that there are no adipocytes in the periosteum, the term was changed to the more descriptive "parosteal lipoma" by Power in 1888. This is a case report of a patient with a chest wall mass that on CT scan and MRI had the typical PL appearance. This pattern allows one to identify the lesion and thus, to differentiate it from malignant conditions.
骨旁脂肪瘤（PL）占所有脂肪瘤的0.3%。它们由毗邻骨皮质的脂肪组织构成，并引发骨质反应性改变。这种通常生长缓慢的惰性病变位于肋骨处并不常见。尽管是良性疾病，但PL的影像学表现可能被误诊为恶性病变。我们报告一例进行了手术活检的PL患者。描述了PL在计算机断层扫描（CT）和磁共振成像（MRI）中的特征性表现。熟悉PL的特征性影像学征象有助于避免进行侵入性诊断检查。脂肪瘤是由成熟脂肪细胞组成的良性肿瘤。它们是最常见的间叶组织肿瘤，占所有软组织肿瘤的50%。其位置从浅表到深部病变各不相同。肌肉骨骼脂肪瘤性病变可位于骨骼、软组织，也可累及关节和腱鞘。PL是一种罕见的良性深部脂肪组织肿瘤，起源于紧邻骨膜处但并非起源于骨膜。1836年，西林首次描述了这种病变并将其命名为“骨膜脂肪瘤”。在认识到骨膜中不存在脂肪细胞后，1888年鲍尔将该术语改为更具描述性的“骨旁脂肪瘤”。这是一例胸壁肿块患者的病例报告，其CT扫描和MRI表现具有典型的PL特征。这种表现模式有助于识别病变，从而将其与恶性疾病区分开来。
