目的:探讨硬化性横纹肌肉瘤(SRMS)的临床病理特征及其与胚胎型横纹肌肉瘤(ERMS)和肺泡型横纹肌肉瘤(ARMS)的区别。
方法:临床,研究了4例SRMS的组织学和免疫组织化学特征。对文献进行了综述。
结果:4例均发生于成人。患者的年龄范围为20至54岁(平均=41.5岁)。男女比例为1:1。肿瘤位于左手腕,右大腿,右侧面部和右侧脸颊,肿瘤大小从2.5cm到10cm不等(平均=5.7cm)。组织学上,SRMS的特点是存在大量的高度透明的基质,模仿类骨质或软骨组织。肿瘤细胞主要由原始的小圆形细胞组成,它们以不同的生长模式排列。包括束状,绳状,单文件,小梁,微肺泡和假血管结构。在1例中发现了一些横纹肌母细胞。在2例中发现了第二个梭形细胞成分,类似梭形细胞横纹肌肉瘤或外周神经鞘瘤。免疫组织化学,所有病例均显示MyoD1弥漫性染色和结蛋白局灶性染色。肌细胞生成素染色常呈阴性。其中3例还表达肌肉特异性肌动蛋白,2例α-平滑肌肌动蛋白阳性。他们都对h-caldesmon持否定态度,S-100蛋白,CD31、CD34、AE1/AE3和间变性淋巴瘤激酶卵白。
结论:SRMS在形态上不同于ERMS和ARMS。然而,最近的细胞遗传学研究表明与ERMS存在组织遗传学关系。熟悉其形态学特征和免疫表型可能有助于将横纹肌肉瘤的这种特殊变体与具有丰富硬化基质的各种病变区分开。
OBJECTIVE: To study the clinicopathologic characteristics of sclerosing rhabdomyosarcoma (SRMS) and its distinction from embryonal rhabdomyosarcoma (ERMS) and alveolar rhabdomyosarcoma (ARMS).
METHODS: The clinical, histologic and immunohistochemical features of 4 cases of SRMS were studied. The literature was reviewed.
RESULTS: All the 4 cases occurred in adults. The age of patients ranged from 20 to 54 years (mean = 41.5 years). The male-to-female ratio was 1:1. The tumor was located in the left wrist, right thigh, right face and right cheek respectively and the tumor size varied from 2.5 cm to 10 cm in dimension (mean = 5.7 cm). Histologically, SRMS was characterized by the presence of large amounts of heavily hyalinized matrix, mimicking osteoid or chondroid tissue. The tumor cells were composed predominantly of primitive small round cells which were arranged in diverse growth patterns, including fascicular, cord-like, single-file, trabecular, microalveolar and pseudovascular structures. A few rhabdomyoblasts were identified in 1 case. A second spindle cell component was focally found in 2 cases, resembling spindle cell rhabdomyosarcoma or peripheral nerve sheath tumor. Immunohistochemically, all cases showed diffuse staining for Myo D1 and focal staining for desmin. The staining for myogenin was often negative. Three of the cases also expressed muscle-specific actin and 2 cases were positive for alpha-smooth muscle actin. They were all negative for h-caldesmon, S-100 protein, CD31, CD34, AE1/AE3 and anaplastic lymphoma kinase protein.
CONCLUSIONS: SRMS differs from ERMS and ARMS morphologically. Recent cytogenetic studies however suggest a histogenetic relationship with ERMS. Familiarity with its morphologic features and immunophenotype may help to distinguish this peculiar variant of rhabdomyosarcoma from a variety of lesions with abundant sclerosing matrix.