皮肤纤维肉瘤

患者女，37岁。因左前臂皮下结节、溃疡伴痛痒6月余来诊。经抗生素系统及局部治疗效果不明显，皮损渐大，从未消退，近1个月溃疡范围明显增大。皮肤科检查：左前臂伸侧近肘关节处可见约5.5 cm × 4.0 cm大小浸润性斑块，表面溃疡形成，伴少许污秽分泌物；皮损境界尚清，质地较硬。皮损组织病理检查：表皮基底层色素增多，瘤组织紧贴表皮，真皮全层及皮下脂肪见多数大小不一的梭形细胞浸润，部分细胞明显异形，核分裂象易见，细胞之间有细小胶原纤维束。免疫组化：黑素瘤相关抗原、细胞角蛋白、HCK、Melan-a、S-100、平滑肌肌动蛋白、CD34、CD68均阴性，纤维连接蛋白（++）。组织病理诊断：纤维肉瘤，Ⅱ级。本病需与隆突性皮肤纤维肉瘤、皮肤梭形鳞状细胞癌、非典型纤维黄瘤、恶性纤维组织肉瘤等鉴别。

Dermatofibrosarcoma: a case report

A 37-year-old female was admitted to the hospital for an itching and painful subcutaneous nodule with ulceration on the extensor aspect of her left forearm for more than 6 months. The pain was severe, continuous and localized. Systemic and local treatment with antibiotics resulted in no obvious improvement. The lesion had gradually increased in size over the past 6 months and the ulcer had enlarged for 1 month. On examination, a hard infiltrative plaque measuring about 5.5 cm × 4.0 cm with a well-defined margin was seen on the extensor aspect of her left forearm, along with ulceration and some dirty discharge on the surface. The diagnosis of fibrosarcoma, grade Ⅱ was eventually made by a biopsy of the lesion, which revealed increased pigmentation in the basal layer, and tumor tissue was tightly adherent to the epidermis. Dermis and subcutaneous fat layer were infiltrated with various sizes of spindle cells with fine collagen fiber bundles between the cells. Obvious atypia and mitotic figures were easily observed in some of the cells. Immunohistochemical analysis showed moderately positive staining for fibronectin, but negative staining for human melanoma black-45 （HMB45）, S100, smooth muscle actin （SMA）, Melan-a, high molecular weight cytokeratin （HCK）, CD34, CD68 or cytokeratin. Some diseases should be differentiated from this case, including dermatofibrosarcoma protuberans, cutaneous spindle cell squamous carcinoma, atypical fibroxanthoma, malignant fibrous histiocytoma, and so on.