Marom E M, Helms C A
Duke University Medical Center, Department of Radiology, Durham, NC 27710, USA.
Skeletal Radiol. 1999 May;28(5):260-4. doi: 10.1007/s002560050512.
To assess the MR imaging characteristics, presenting symptoms, age and nerve distribution of fibrolipomatous hamartoma.
A computer search was performed of the term fibrolipomatous hamartoma through the musculoskeletal section MR imaging results at our institution from June 7, 1996 to January 21, 1998 followed by a search of the terms lipomatous hamartoma, median nerve, surrounding fat, increased fatty signal, coaxial, and neuroma. MR images and medical files were retrospectively reviewed by two experienced musculoskeletal radiologists for imaging characteristics, nerve and age distribution as well as for history of trauma. In addition three consultation cases from outside institutions were added for determination of image characteristics.
Ten fibrolipomatous hamartomas were identified: eight in the median nerve, one in the ulnar nerve and one in the sciatic nerve. Mean age was 32.3 years (range 4-75 years, SD 21 years). Imaging characteristics were serpiginous low-intensity structures representing thickened nerve fascicles, surrounded by evenly distributed fat, high signal intensity on T1-weighted sequences and low signal intensity on T2-weighted sequences. The amount of fat varied; however, distribution in eight cases (80%) was predominantly between nerve fibers rather than surrounding them peripherally. All had a coaxial-cable-like appearance on axial planes and a spaghetti-like appearance on coronal planes that was not seen in any other type of median nerve abnormality imaged during the study period.
The MR imaging characteristics of fibrolipomatous hamartoma are pathognomonic, obviating the need for biopsy for diagnosis.
评估纤维脂肪性错构瘤的磁共振成像（MR）特征、临床表现、年龄及神经分布情况。
通过计算机检索我院1996年6月7日至1998年1月21日期间肌肉骨骼系统MR成像结果中“纤维脂肪性错构瘤”一词，随后检索“脂肪性错构瘤”“正中神经”“周围脂肪”“脂肪信号增强”“同轴”及“神经瘤”等词。两名经验丰富的肌肉骨骼放射科医生对MR图像和病历进行回顾性分析，以确定成像特征、神经及年龄分布情况以及外伤史。此外，增加了三例来自外院的会诊病例以确定图像特征。
共识别出10例纤维脂肪性错构瘤：8例位于正中神经，1例位于尺神经，1例位于坐骨神经。平均年龄为32.3岁（范围4 - 75岁，标准差21岁）。成像特征为呈匐行性的低强度结构，代表增厚的神经束，周围为均匀分布的脂肪，在T1加权序列上呈高信号强度，在T2加权序列上呈低信号强度。脂肪含量各不相同；然而，8例（80%）的脂肪主要分布在神经纤维之间，而非在神经纤维周围。在轴位平面上均呈同轴电缆样外观，在冠状位平面上呈意大利面条样外观，这在研究期间成像的任何其他类型的正中神经异常中均未见到。
纤维脂肪性错构瘤的MR成像特征具有诊断特异性，无需活检即可诊断。
