Division of Plastic Surgery, Department of Surgery, National Taiwan University Hospital, College of Medicine, Taipei, Taiwan.
Division of Plastic Surgery, Department of Surgery, Far Eastern Memorial Hospital, New Taipei City, Taiwan.
Asian J Surg. 2019 Aug;42(8):832-838. doi: 10.1016/j.asjsur.2018.12.012. Epub 2019 Jan 30.
Atypical lipomatous tumor (ALT) is a low-grade malignancy that frequently occurs at a subfascial anatomical location. While marginal excision is adequate for lipomas, excision with a surgical margin is suggested for ALTs. However, ALTs and lipomas are difficult to differentiate preoperatively, even with the help of imaging studies. In this study, we aimed to formulate a scoring system based on selected clinical and imaging characteristics to enhance the accuracy of pre-operative diagnosis of deep-seated ALTs.
We enrolled 417 cases of deep-seated lipoma and 53 cases of ALTs from soft tissue treated between 2005 and 2016. Tumors arising from the bone, internal cavities, retroperitoneum, or nervous system were excluded. Clinical data were analyzed along with magnetic resonance image (MRI) features. We further developed a scoring formula to distinguish deep-seated ALTs from lipomas.
Older age, tumor location at lower limbs, and the presence of MRI features (larger size, thick septa > 2 mm, contrast enhancement>1 cm, fat component <75%) are identified as risk factors of ALT and were utilized to develop a scoring system for distinguishing ALTs from lipomas. The formula exhibited 90% sensitivity and 92.5% specificity, and a score more than 0.214 suggested a diagnosis of ALT.
The scoring system developed in this study can facilitate the pre-operative diagnosis of deep-seated ALTs and lipomas. If ALT is suspected, further tumor biopsy followed by molecular diagnosis can establish a definite diagnosis. Therefore, this scoring system can serve as a cost-effective tool for the clinical management of deep-seated lipomatous tumors.
非典型性脂肪肉瘤（ALT）是一种低度恶性肿瘤，常发生于筋膜下解剖位置。对于脂肪瘤，边缘切除即可，而对于 ALT，则建议进行带外科边缘的切除。然而，即使借助影像学研究，术前也很难区分 ALT 和脂肪瘤。本研究旨在制定一个基于选定临床和影像学特征的评分系统，以提高深部 ALT 术前诊断的准确性。
我们纳入了 2005 年至 2016 年间软组织治疗的 417 例深部脂肪瘤和 53 例 ALT 病例。排除起源于骨、体腔、腹膜后或神经系统的肿瘤。分析了临床数据和磁共振成像（MRI）特征。我们进一步开发了一个评分公式，以区分深部 ALT 和脂肪瘤。
年龄较大、肿瘤位于下肢，以及 MRI 特征（较大的大小、厚间隔>2mm、对比增强>1cm、脂肪成分<75%）被确定为 ALT 的危险因素，并用于开发区分 ALT 和脂肪瘤的评分系统。该公式的敏感性为 90%，特异性为 92.5%，评分>0.214 提示诊断为 ALT。
本研究建立的评分系统有助于深部 ALT 和脂肪瘤的术前诊断。如果怀疑为 ALT，则进一步进行肿瘤活检和分子诊断可明确诊断。因此，该评分系统可作为深部脂肪肉瘤临床管理的一种具有成本效益的工具。
