浅表性CD34阳性的纤维母细胞肿瘤1例报道并文献复习

Superficial CD34-positive fibroblastic tumor:a case report and review of literature

目的探讨浅表性CD34阳性的纤维母细胞肿瘤(SCPFT)独特的临床病理特征及鉴别诊断要点。方法对1例发生在肩部的SCPFT进行HE和免疫组化染色检查,观察其组织形态及免疫表型特点,并复习相关文献。结果患者,男性,25岁,无意间发现右肩部占位。肿块边界清,位于真皮层,无包膜。镜下肿块位于真皮深层,边界相对清楚,肿瘤由梭形细胞、胖梭形细胞及多边形细胞组成,呈束状、交织排列,局部可见奇异形/多形性细胞核;部分瘤细胞胞质呈空泡状,呈黄色瘤样;核分裂罕见,间质内淋巴细胞散在或局灶浸润。免疫组化:CD34和vimentin弥漫(+),EMA、S-100、SMA、desmin、CD31、CK-Pan、CD68、STAT6、bcl-2、CD99、Fli-1、HMB45(-),INI1无表达缺失,Ki-67核阳性比例<2%。结论 SCPFT罕见,其诊断主要依据独特的组织学形态及免疫组化表型,需要与非典型性纤维组织细胞瘤、非典型性纤维黄色瘤、未分化多形性肉瘤等其他多形性间叶性肿瘤鉴别,以避免误诊及过度治疗。

Objective To investigate the clinicopathological features and differential diagnosis of superficial CD34-positive fibroblastic tumor(SCPFT).Methods A case of SCPFT in the shoulder was examined by HE and immunohistochemical staining.The morphological and immunophenotypic characteristics of the tumor were observed and the relevant literatures were reviewed.Results The patient was a 25-year-old male and presented with a lump in the right shoulder accidentally.Grossly,the lump was well circumscribed and located in the deep dermis without capsule.Microscopically,the tumor was located in the deep dermis,circumscribed relatively.The tumors were composed of spindle cells,fat spindle cells and polygonal cells,with highly pleomorphic and bizarre nuclei and mitosis was rare,focally showed xanthomatous changes.Lymphocytes distributed scattered or focally in the background.Immunohistochemistry showed that the neoplastic cells were diffusely positive for CD34 and vimentin,and negative for EMA,S100,SMA,Desmin,CD31,CK-Pan,CD68,STAT6,Bcl-2,CD99,FLI-1 and HMB45,the INI1 expression was loss.The proliferation index of Ki67 was less than 2%.Conclusions SCPFT is rare,and it needs to be differentiated from other pleomorphic mesenchymal tumors such as atypical fibrous histiocytoma,atypical fibroxanthoma,undifferentiated pleomorphic sarcoma and to prevent the misdiagnosis and overtreatment.