腺泡状软组织肉瘤的影像学表现

Imaging Features of Alveolar Part Tissue Sarcomas

目的探讨腺泡状软组织肉瘤（ASPS）的影像学表现特征,旨在提高对该类疾病的诊断水平。方法回顾性分析经手术病理证实的ASPS患者11例（男6例,女5例,年龄21-62岁,平均32.1岁）,所有患者均行MRI平扫,其中4例行MR增强扫描,1例行MR增强扫描与MRA,2例行MRS扫描,2例行CTA检查。结果 ASPS在影像学上主要表现为T1WI等信号或稍高信号、T2WI混杂高信号（11/11）的软组织肿块,边界清楚,呈球形或类球形（9/11）,肿瘤内外可见多发扭曲的血管流空信号（8/11）与线状低信号分隔（9/11）。增强扫描肿瘤实质部分呈明显强化（5/5）。MRA示肿瘤有丰富的供血动脉（匹配于平扫序列中的流空信号区）以及多发紊乱的引流静脉。2例1H-MRS均表现为3.2 ppm处出现明显的胆碱峰。ASPS容易发生在年轻患者;肿瘤没有特定的好发部位,但更趋向于躯干的中下段（7/11）,部分患者就诊时已经发生远处转移（肺4例,脑1例,淋巴结2例）。结论 ASPS虽为罕见肿瘤,但其影像学表现及临床征象具有一定特征性,熟悉这些特点,有利于ASPS的诊断。

Objective Alveolar soft part sarcoma（ ASPS） is an extremely rare soft tissue neoplasm and researches concerning its radiological features have not been comprehensive. This paper aims to investigate its imaging features. Methods A total of 11 patients with pathologically-proved ASPS,who were encountered at authors＇ hospital during the period from Jan. 2005 to Apr. 2014,were enrolled in this study. The patients included 6 males and 5 females with a mean age of 32. 1years old（ 21- 62 years old）. The clinical data were retrospectively analyzed. Plain MRI was performed in all patients,and additional enhanced MRI was employed in 4 patients,enhanced MRI plus MR angiography（ MRA） in one patient,MRS in 2 patients and CT angiography（ CTA） in 2 patients. Results ASPS presented as a round or oval,well-defined soft tissue mass with iso-signal or slight hyper-signal on T1 WI and mixed hyper-signal on T2WI（ 11 /11）. Multiple tortuous vascular flow void signals（ 8 /11） and low signal linear septum（ 9 /11） could be observed. Enhanced scan showed that the solid part of the lesion became obviously enhancement（ 5 /5）. MRA revealed abundant tumor-feeding arteries,which were corresponding to the flow void signals observed on plain scanning sequence,and multiple disordered draining veins. In 2patients,MRS showed a slight higher choline（ cho） peak at 3. 2ppm. ASPS mainly occurred in younger people; the most common site for the primary tumor was the middle and lower part of the torso（ 7 /11）. Distant metastases had already been present in some patients,including lung（ n = 4）,brain（ n = 1） and lymph nodes（ n = 1）,at their first medical visit.Conclusion Although alveolar soft part sarcoma is a rare tumor,it carries certain imaging characteristics,which are very helpful for its diagnosis.