骨外黏液样软骨肉瘤3例临床病理观察

Extraskeletal myxoid chondrosarcoma:a clinicopathologic observation

目的探讨骨外黏液样软骨肉瘤的临床病理特征及鉴别诊断。方法应用HE、免疫组化染色观察3例骨外黏液样软骨肉瘤的组织学形态及免疫组化特征,并复习文献。结果3例中女性2例,男性1例,年龄30～52岁;2例发生于大腿,1例发生于手部,肿块均位于深部软组织。光镜下肿瘤呈多结节状,结节由纤维、疏松纤维血管组织分隔形成大小不等的小叶,结节内为丰富的黏液样基质,小叶周边区细胞丰富,中央区细胞稀疏;瘤细胞为圆形、卵圆形及短梭形,排列呈索状或吻合条索状;病灶内可见灶性出血,无坏死,未见明确软骨分化。免疫组化:肿瘤细胞vimentin均(+),2例NSE和Syn(+),1例S-100和CgA(+),1例EMA灶性(+);CK、HHF35、desmin、actin和GFAP均(-)。结论骨外黏液样软骨肉瘤是一种罕见的恶性软组织肿瘤,具有特征性的组织病理学特点,可伴有神经内分泌分化;虽然生长缓慢,但易转移和局部复发,需长期随访。

To study the clinicopathological features and differential diagnosis of extraskeletal myxoid chondrosarcoma The features of histopathology and immunophenotype of EMC were studied by means of HE and immunohistochemical stains in 3 cases, with review of the literatures. Results The age of the 2 females and 1 male ranged from 30 to 52 years. All tumors occurred within the deep soft tissues, with 2 cases occurring in the thigh and 1 case in the hand. Microscopically, a muhinodular architecture with fibrous or loose fibrovascular septa separating lobules of various sizes was characteristic. Each lobule contained abundant myxoid stroma, in which tumor cellularity was increased at the periphery of the lobules. The cells were arranged in anastomosing strands or cords. Foci of intralesional hemorrhages were seen, with absence of necrosis. No mature hyaline cartilage was found in any of the cases. Immunohistochemically, the tumor cells were positive for vimentin, NSE and synaptophysin expressed in case 1 and case 3, S100 protein and CgA were observed in case 1, EMA showed focal posidvity in case 2, but negative for CK, HHF35, desmin, actin and GFAP in all cases. Conclusion EMC is a rare soft tissue sarcoma, characterized by distinctive histopathological features and often shows neuroendocrine differentiation. Although EMC is a slow-growing tumor, it has a very high rate of local recurrences, and even metastases, and long-term follow-up should be stressed.