甲状腺及臀部孤立性纤维性肿瘤2例报道及临床病理学分析

Solitary fibrous tumor of the thyroid gland and buttock:Report of two cases

目的:探讨孤立性纤维性肿瘤(solitary fibrous tumor,SFT)的临床、病理组织学、免疫组织化学等特点。方法:报道2例原发于罕见部位的SFT。例1发生在男性右甲状腺,例2发生在女性左臀部。观察2例罕见部位SFT病理组织学特点及免疫组织化学结果。结果:甲状腺及臀部的肿块最大径分别为4.5cm和7cm,两例均为单个孤立的椭圆形结节,有纤维性假包膜。镜下甲状腺SFT与其它文献报道相符合,呈良性形态,臀部SFT局灶肿瘤细胞密集具有非典型性并有出血、坏死,核分裂<4/10HPF。免疫组化染色两例均示肿瘤细胞表达CD34、Vimentin、Bcl-2及CD99阳性。例1甲状腺标记物TG,TTF-1肿瘤细胞表达阴性。结论:发生在甲状腺和臀部的SFT均属罕见。与其他部位发生的肿瘤具有相同的病理组织学特点和免疫组化表达,肿瘤细胞呈梭形和卵圆形,有血管外皮瘤样组织学特点,伴有硬化区和多量胶原纤维。因SFT组织学形态多样性,易与其他软组织肿瘤混淆,正确诊断有赖于病理组织学形态及免疫组化特点。甲状腺SFT多为良性,臀部SFT易发恶性,因SFT生物学行为的不定性,需要长期随访。

Objective：To explore the clinicopathologic and immunohistochemical features of the solitary fibrous tumor（SFT）.Methods： We described two cases of primary solitary fibrous tumor in rare position for their histopathology and immunohistochemical features.One patient was men and lesion was located in right thyroid gland,another patient was women and lesion was located in left buttock.Results： The greatest diameter of the mass in thyroid gland and buttock was 4.5cm and 7cm,both of the tumors were well circumscribed.Histologically,the solitary fibrous tumor of thyroid gland（T-SFT） was similar with reported cases and showed benign pattern.The tumor cells of buttock SFT（B-SFT） had high cellularity,cellular pleomorphism,haemorrhage,necrosis,and mitotic activity less 4/10 HPF.Immunophenotype： T-SFT and B-SFT were positive for CD34,vimentin,Bcl-2 and CD99,tumor cells of the thyroid gland negative for TG and TTF-1.Conclusion： Solitary fibrous tumor arising in the thyroid gland and buttock is rare,it has the same histopathology and immunohistochemical features with neoplasms that occur in other sites.SFT has many histological features and can be diagnosed by histological and immunohistochemical findings from other soft tissues neoplasms.T-SFT is benign but B-SFT has malignant histologic characteristics.The behavior of tumor is unpredictable and therefore a long-term follow up seems necessary.