肺恶性孤立性纤维性肿瘤2例临床病理观察

Clinicopathological features of intrapulmonary malignant solitary fibrous tumor

目的探讨肺恶性孤立性纤维性肿瘤（MSFT）的临床病理学特征、鉴别诊断及预后。方法结合文献对2例肺MSFT的临床资料、病理学形态及免疫表型进行分析并随访。结果 2例均为男性,年龄分别为49岁和58岁。发生部位均为左肺下叶,均隐匿性起病。肿瘤大小分别为5.6 cm×5.5 cm×3.5 cm及20 cm×18 cm×15 cm。镜检示细胞密集区和细胞稀疏区交替分布,肿瘤细胞间有玻璃样变胶原纤维分隔。密集区肿瘤细胞丰富,呈束状、旋涡状排列,瘤细胞呈短梭形,异型性明显,有肿瘤性坏死和较多核分裂（〉4个/10 HPF）。免疫组化示肿瘤细胞CD34、bcl-2、CD99及vimentin（＋）,Ki-67增殖指数5%-30%;calretinin、S-100、desmin、SMA、CD117、CK、EMA、MC、Dog-1、p53和TTF1均（-）。结论肺MSFT非常罕见,确诊主要依靠病理形态学及免疫组化标记,并应与肺的其他梭形细胞肿瘤进行鉴别。治疗以手术完全切除为主,并注意长期随访。

Objective To investigate the clinicopathological features,diagnosis and differential diagnosis,treatment,and prognosis of intrapulmonary malignant solitary fibrous tumor（ MSFT）. Methods Two cases of intrapulmonary MSFT were studied with routine morphological observation and immunohistochemical staining. The associated literatures were reviewed to discuss the key points of the diagnosis and the differential diagnosis. Results One patient was a 49-year-old man without obvious clinical features. Another case was a 58-year-old man with 2 months history of chest stuffiness. The tumors from 2 cases were 5. 6 cm × 5. 5 cm × 3. 5 cm and 20 cm × 18 cm × 15 cm in size. Histologically,the tumor was composed of areas of alternating hypercellularity and hypocellularity which were separated by dense collagenous fibrous stroma. In hypercellular areas,the tumor cells were spindle to short-spindle shaped and arranged in fascicular or storiform pattern. The tumor cells showed marked nuclear atypia,increased mitotic activity（ 4 /10 HPF） and coagulative necrosis.Immunohistochemically,the tumor cells were diffusely positive staining for CD34,bcl-2,CD99,vimentin,while negative staining for calretinin,S-100,desmin,SMA,CD117,CK,EMA,MC,Dog-1,P53 and TTF1. Ki-67 labelling index was5%- 30%. Conclusion The intrapulmonary MSFT is very rare. Diagnosis is based on its pathological morphology and immunohistochemistry. Differential diagnosis includes other spindle-shaped cell tumors of the lung,such as fibrosarcoma,MFH,MPNST,etc. The treatment is complete surgical resection,and a long-term follow-up is required.