黏液型隆突性皮肤纤维肉瘤6例临床病理分析

Myxoid dermatofibrosarcoma protuberans:a clinicopathological analysis of 6 cases

目的探讨黏液型隆突性皮肤纤维肉瘤的临床病理学特征、诊断及鉴别诊断。方法对6例黏液型隆突性皮肤纤维肉瘤进行临床病理学分析。结果本组男性3例,女性3例,年龄8个月～42岁,平均年龄29岁。主要表现为缓慢生长的皮肤或皮下结节性肿块。肿瘤位于腹壁2例,前额、胸壁、腹股沟区和臀部各1例。肿瘤直径为1.5～4.5 cm,平均直径2.9 cm;切面灰白、灰黄色,质实到胶样。镜下肿瘤间质黏液变性>50%,背景血管明显。肿瘤细胞排列成实性片状或模糊的结节状,席纹状结构不明显;瘤细胞温和,梭形或星芒状,胞质淡染,胞界不清。所有病例均可见典型隆突性皮肤纤维肉瘤特征性的脂肪蜂窝状生长构型。6例中4例见经典型隆突性皮肤纤维肉瘤成分,1例伴巨细胞纤维母细胞瘤图像,1例部分区域为纤维肉瘤样隆突性皮肤纤维肉瘤。免疫组化示6例均至少局灶CD34(+),S-100和SMA均(-)。4例获得随访,随访时间为3个月～3年,2例局部复发,未见转移。结论黏液型是隆突性皮肤纤维肉瘤的形态学亚型之一,其临床表现和生物学行为与经典型相同,认识这种亚型的组织学特征有助于正确诊断和鉴别诊断。

Abstract： Objective To study the clinicopathologic features, diagnosis and differential diagnosis of the myxoid variant of dermatofibrosareoma protuberans （DFSPs）. Methods Six cases of myxoid dermatofibrosarcoma protuberans were observed for the morphological features. Results Among the 6 cases studied, 3 were male and 3 were female, aged 29 years （range from 8 months to 42 years）. Tumors presented as slowly growth nodules in dermatosis and might involve in the subcutaneous fatty tissue or muscle. Locations included the abdominal wall （two cases） , forehead, chest, inguinal area, and buttocks （ one each ）. The patients were treated by wide excision as well as reexcision. Tumor size ranged from 1.5 to 4.5 em（ median 2. 9 cm）. Grossly, the tmnors were tan to yellow in color, firm to gelatinous soft tissue masses. Histologically, tumor stroma ranged from 50 to 100% myxoid, and prominent thin-walled vessels were observed. Tumor cells, spindled to stellated, relatively uniform, containing indistinct palely eosinophilic cytoplasm, arranged in infiltrative sheet-fike pattern or vaguely nodular growth with peripheral diffuse infiltration, instead of the classical storiform pattern. All cases could be found honeycomb infiltration of fat and 4 cases showed cellular areas of more typical DFSP, 1 showed areas of giant cell fibroblastoma and 1 showed progression to fibrosarcomatous DFSP. Immunohistochemically, all cases were at least focally positive for CD34 and were negative for S100 and muscle markers. Available clinical follow-up in 4 cases, ranging from 3-36 months, （median follow-up 16 mouths ）, revealed local recurrence in 2 cases and no evidence of metastasis. Conclusions Myxoid dermatofibrosarcoma protuberans is a histological subtype of DFSP, with clinical features and behavior similar to typical DFSP, but their unusual morphology is easily confused with a variety of other myxoid mesenchymal neoplasms.