腺泡状软组织肉瘤的影像学特征及临床病理表现

Radiological features and clinicopathological findings of alveolar soft part sarcomas

背景与目的:腺泡状软组织肉瘤罕见,其影像学表现至今尚未见系统研究,本文旨在探讨腺泡状软组织肉瘤(alveolar soft part sarcomas,ASPS)的临床特征和影像学表现,以提高诊断的准确率。方法:回顾性分析10例经病理证实的腺泡状软组织肉瘤的临床特征和影像学表现,所有患者(术前或活检前)均行X线、CT或MR检查。其中,9例行X线平片检查,9例行CT检查,6例行MRI检查。所有切除或活检组织均行HE染色,5例患者有比较完整的免疫组化结果。结果:ASPS发病年龄较轻,80%(8/10)为30岁以下。多表现为无痛性肿块。3例就诊时已有肺转移。70%(7/10)发生于下肢深部软组织以及臀部。另3例分别位于胸壁、颈部及眼眶内。ASPS的CT表现为软组织肿块影,增强后呈明显不均匀强化。MRI表现为T1WI等或略高信号,T2WI高信号,肿瘤内外可见血管流空信号,增强后肿瘤呈不均匀明显强化。镜下ASPS是由嗜伊红色的大多边形上皮样细胞组成,呈特征性的器官样或腺泡状排列,腺泡之间为衬覆单层扁平内皮细胞的裂隙状或血窦样毛细血管网。免疫组化显示3例神经元特异性烯醇化酶(NSE)阳性,两例抗淀粉酶消化染色(PAS)阳性,1例MyoD1横纹肌特异肌调节蛋白阳性(胞质染色),1例Desmin结蛋白阳性。结论:ASPS虽然是少见软组织肉瘤,但影像学很有特点,结合临床、影像和病理表现是诊断的关键。

Background and purpose： Alveolar soft tissue sarcoma（ASTS） is rare and there is no systematic research on its radiological features. The purpose of this article was to investigate the clinicopathological and radiological imaging features of alveolar soft tissue sarcoma（ASTS） and to improve the diagnostic accuracy. Methods： Clinical features and radiological findings of ten patients with histologically confirmed ASTS were retrospectively analyzed. X-ray, CT or MRI was performed before surgery or biopsy. Nine of the ten cases had X-ray examinations. Nine cases underwent multi-slice spiral CT scan and six cases had MR imaging. All ablated or biopsy masses had HE stained and 5 cases with intact data of immunohistochemistry. Results： 8 of 10 patients with ASTS were relatively young with the age of no more than 30 years old and usually presented as a painless mass. 7 of 10 cases（70%） were located in the deep soft tissues of the glutaeofemoral areas. The other 3 cases occurred in chest wall, cervical and orbital areas. Three patients had lung metastases at first diagnosis. CT scan showed a soft tissue mass with obviously disparity enhancement. ASTS typically showed hyper- or iso-intensity relative to muscle on Tt-weighted images, and high signal intensity on T2-weighted images, with multiple intra and extra tumor signal voids of vessels. The contrast enhancement of ASTS was usually obvious and heterogeneous on MRI. Histologically, all tumors were composed of large, uniform, epithelioid cells with abundant eosinophilic, granular cytoplasm arranged in solid nests and/or alveolar structures, separated by thin, sinusoidal vessels. Immunohistochemically, 3 cases were positive for NSE, 2 cases for PAS,one case for MyoDl（cytoplasmic staining）and one positive for desmin. Conclusion： ASTS is a rare type of soft tissue sarcomas. However, it has unique radiological characteristics. Radiological findings correlated with clinicopathological features are the key to diagnosis.