肺原发性滑膜肉瘤11例临床病理分析及SS18-SSX融合基因检测

Clinicopathologic analysis and SS18-SSX fusion gene detection in 11 cases of primary pulmonary synovial sarcoma

关键词:  肺原发性滑膜肉瘤  临床病理学  SS18-SSX融合基因

Key words:  primary pulmonary synovial sarcoma  clinicopathology  SS18-SSX fusion gene

摘要:

目的　探讨肺原发性滑膜肉瘤（PPSS）的临床病理特征和SS18-SSX融合基因检测意义。 方法　回顾性分析11例PPSS患者临床病理资料，其中男8例，女3例，年龄19～56岁，主要症状有咳嗽、咯血及胸痛，X线表现为患侧肺野团块状阴影，CT检查显示病变呈圆形或卵圆形，边缘均光滑，未见毛刺征。对肿瘤进行免疫组化染色，并用荧光原位杂交法（FISH）检测SS18-SSX融合基因。结果　11例PPSS中7例为单相型滑膜肉瘤，由形态一致的长梭形细胞构成，细胞胞质稀少、边界不清，呈片或束状排列；4例为双相型滑膜肉瘤，由不同比例的上皮和梭形细胞成分构成，上皮成分形成腺样或裂隙样结构，或排列呈乳头状、巢状、条索状。免疫组化染色显示肿瘤细胞弥漫表达Vimentin、TLE-1、CD99和Bcl-2，不同程度表达CK、EMA；1例表达S100，1例表达CD34，2例表达SMA，均为局灶性表达；所有肿瘤细胞均不表达TTF1、STAT6、Desmin、CR、D2-40、CK5/6、WT-1。FISH检测显示11例PPSS中10例可见SS18-SSX融合基因。结论　PPSS是罕见的肺原发性恶性肿瘤，形态可呈单相型、双相型，故应与发生于肺的恶性间皮瘤、纤维肉瘤等肿瘤相鉴别，SS18-SSX融合基因检测联合免疫组化染色有助于明确诊断。

Abstract:

Objective To investigate clinicopathologic characteristics and the significance of SS18-SSX fusion gene detection in primary pulmonary synovial sarcoma (PPSS). Methods The clinicopathologic data of 11 PPSS patients were reviewed retrospectively. The patients were aged 19-56 years, including 8 males and 3 females. The main symptoms were cough, hemoptysis and chest pain. X-ray showed massive shadow in the lung field. CT examination showed the lesion was round or oval, with smooth edges and no burr sign. All cases of PPSS were analyzed by immunohistochemistry and SS18-SSX fusion gene was detected by fluorescence in situ hybridization (FISH). Results Seven cases were monophasic fibrous type synovial sarcoma, which consisted of sheets or fascicles of uniform, elongated spindle cells with scant cytoplasm and indistinct cell borders. Four cases were biphasic synovial sarcoma, which had variable proportions of spindle and epithelioid cells. The epithelioid component contained gland- and/or slit-like structures or papillary structures and the epithelioid cells also formed solid nests or cords. Immunohistochemical studies showed that tumor cells were diffusely expressing vimentin, TLE-1, CD99, Bcl-2 and partly expressing CK(AE1/AE3) and EMA. One case was positive for S100，1 positive for CD34, 2 positive for SMA; whereas tumor cells were negative for TTF1, STAT6, desmin, CR, D2-40, CK5/6 and WT-1 in call cases. SS18-SSX fusion gene was detected in 10 cases by FISH. Conclusion PPSS is a rare primary pulmonary malignant tumor, which can be monophasic or biphasic. Therefore, it should be differentiated from malignant mesothelioma, fibrosarcoma and other tumors occurring in the lung. SS18-SSX fusion gene detection and immunohistochemical stainings can help to confirm the diagnosis.