硬化性上皮样纤维肉瘤的诊断与鉴别诊断

SCLEROSING EPITHELIOID FIBROSARCOMA

目的 探讨硬化性上皮样纤维肉瘤的组织学诊断及鉴别诊断。 方法 对２ 例硬化性上皮样纤维肉瘤进行临床病理学和免疫组织化学研究。 结果 ２ 例均为成年患者，临床表现为右大腿无痛性缓慢生长的肿块。大体上肿瘤呈结节状或分叶状，无包膜，质地坚韧而有弹性感。组织学上具有两种特征性的形态：其一为瘤细胞胞浆透亮，似上皮细胞，排列成条束状、巢状、片状或腺泡状；其二为肿瘤的间质中大量胶原纤维发生透明样变性，形成硬化性的基质。免疫组织化学标记显示上皮样的瘤细胞强阳性表达波形蛋白（ｖｉｍｅｎｔｉｎ） ，部分弱阳性表达上皮膜抗原（ＥＭＡ） 而细胞角蛋白（ＣＫ）、Ｓ１００、平滑肌肌动蛋白（αＳＭＡ）、结蛋白（Ｄｅｓｍｉｎ） 及黑色素瘤相关抗原（ＨＭＢ４５） 均为阴性。 结论 硬化性上皮样纤维肉瘤是一种低度恶性的纤维肉瘤。

PURPOSE To evlauate the reliability of diagnostic criteria of sclerosing epithelioid fibrosarcoma(SEF)with emphasis on differential diagnosis.METHODS We report two cases of this peculiar carcoma with a clinico pathologic and immunohistochemical study.RESULTS The patients are both adults.The tuomor was located in the thigh,which was painless and grew slowly. Macroscopically,it was described as bosselated or lobulated and non encapsulated.The cut surface was gray white,firm to elastic in consistency.Microscopically,the lesion was characterized by two distinctive features:one is the proliferation of rather uniform,round to ovoid epithelioid cells with clear cytoplasm arranged in cords,nests,sheets or in alveolar pattern;the second is the prominent hyaline sclerosis.Immunohistochemically,the epithelioid tumor cells showed strong immunoreactivity to vimentin,while a substantial minority expressed EMA,but CK,S100,α SMA and desmin were all negative.CONCLUSIONS Sclerosing epithelioid fibrosarcoma is a low grade variant of fibrosarcoma.Despite its slow growth and deceptively bland cytology,it is capable of local recurrences and metastases.Histologcally,it should be differentiated from a variety of benign and malignant lesions which have the epithelioid appearance and sclerosing matrix.