摘要目的 探讨色素性隆突性皮肤纤维肉瘤(PDFSP)的病理学特征、诊断及鉴别诊断.方法 对7例PDFSP患者的临床资料、病理学检查、免疫表型、治疗及预后进行总结,荧光原位杂交(FISH)检测COL1A1/PDGFB融合基因表达,并结合相关文献进行讨论.结果 7例PDFSP患者,男4例,女3例,患者平均年龄47岁,其中5例为复发病例,病史1～50年不等.4例肿瘤位于腰背部.4例最初误诊误治为血管瘤.镜下PDFSP表现为浸润性生长的梭形肿瘤细胞排列成席纹状,无明显边界,其间散在分布不等量的含黑色素的双极或多极的树突状细胞,色素沉着程度不等,细胞异型性轻,偶见核分裂象.1例肿瘤伴有纤维肉瘤变.免疫组织化学显示梭形肿瘤细胞CD34和波形蛋白弥漫强阳性,而HMB45、Melan A、S-100蛋白、结蛋白、CD68及α-平滑肌肌动蛋白(SMA)阴性.脱色素处理后,色素细胞HMB45、Melan A、S-100蛋白和波形蛋白阳性比例分别为4/7、4/7、5/7和7/7.Ki-67阳性指数为1％～8％.4例肿瘤成功进行了COL1 A1/PDGFB融合基因FISH检测,其中3例检测到融合信号,表明PDFSP具有与经典隆突性皮肤纤维肉瘤(DFSP)相同的遗传背景.7例患者中3例行扩大切除术,4例行肿瘤切除术.5例随访12 ～ 123个月,其中2例局部复发,行扩大切除术的3例患者未见肿瘤复发及转移.结论 PDFSP是一种罕见而独特的DFSP亚型,组织学起源未定,生物学行为属交界恶性/潜在低度恶性,提高对PDFSP的认识,可避免病理诊断中的陷阱和误诊.

abstractsObjective To investigate the clinical pathological features,diagnosis and differential diagnosis of pigmented dermatofibrosarcoma protuberance (PDFSP).Methods The clinical history,histopathological features,immunohistochemical characteristics,treatment and prognosis were analyzed in seven cases of PDFSP.Fluorescence in situ hybridization (FISH) was used to detect the expression of COL1A1/PDGFB fusion gene,and related literature was reviewed.Results The median age of the seven patients (4 females,3 males) was 47 years with the tumors involving mostly the trunk (four cases).Histologically,PDFSP showed a cellular lesion composed of spindle cells arranged in short fascicles that form a distinct storiform pattern,and the pigmented bipolar or muhipolar dendritic cells were present with tentacle like processes emanating from a nucleus containing zone.One case showed fibrosarcomatous change.The pigment was tinctorially similar to melanin.The spindle cells were positive for CD34 and vimentin,but negative for HMB45,Melan A,S-100,desmin,CD68 or α-SMA.HMB45,Melan A,S-100 and vimentin were expressed in the melanin containing cells in 4,4,5 and 7 cases,respectively.The labeling index of Ki-67 was 1％-8％.Among the 4 cases successfully examined by FISH,3 showed t(17;22) (q21 ;q13) which suggested COL1A1/PDGFB fusion gene.Three patients were treated by wide local excision and four were treated by simple surgical excision.Two patients developed recurrences during the follow-up period of 12 to 123 months.Of those treated by wide local excision,none developed recurrence.No patient died in the follow-up period.Conclusions PDFSP is a rare pigmented variant of DFSP and an intermediate grade malignant tumor.The origin of the tumor cells is still controversial.Surgical pathologists and dermatopathologists need to be aware of the prototypical histological appearance of PDFSP as there is a risk of misdiagnosing it as either pigmented tumors associated with neurocutaneous syndromes or a highly malignant melanocytic neoplasm.