皮肤假血管肉瘤型鳞状细胞癌临床病理观察

Clinicopathologic analysis of cutaneous pseudoangiosarcomatous squamous cell carcinoma

目的提高对易误诊为血管肉瘤的皮肤假血管肉瘤型鳞状细胞癌的认识。方法报道2例皮肤原发的假血管肉瘤型鳞状细胞癌。结果例1女性，71岁，皮损位于右小腿远端；例2男，57岁，皮损位于右颈部。皮损均为单发的溃疡性肿块。光镜下棘层显著松解形成假血管腔隙，内含游离肿瘤细胞和红细胞，腔隙内衬多角形或扁平、鞋钉样细胞。瘤细胞上皮样，异形性明显，核分裂象易见，胞质丰富，空泡状，核仁明显。肿瘤间质疏松，可见嗜碱性黏液样基质，局部区域弥漫出血坏死。免疫表型panCK、CK5／6、Vim、CK14、EMA、P63及P53阳性，血管内皮标记CD31、CD34、F8、Fli-1阴性。电镜下肿瘤胞质内存在少量的张力原纤维及典型的桥粒结构。结论皮肤原发的假血管肉瘤型鳞状细胞癌是一种鳞状细胞癌亚型，需要与血管肉瘤、上皮样肉瘤等恶性肿瘤进行鉴别。

Objective To improve the knowledge on cutaneous pseudoangiosarcomatous squamous cell carcinoma （PASCC） which could be easily mistaken for angiosarcoma. Methods Two cases of uncommon primary PASCC were studied clinically, pathologically and immunohistochemically. Electron microscopy was also used to observe lesion specimens. Results The patients were a 71-year-old female and a 57-year-old male. A single ulcerative mass was observed on the fight distal leg in the female patient and on the right neck in the male patient. Pathologically, acantholytic tumor cells formed lumina of pseudovascular spaces which contained dissociative tumor cells as well as erythrocytes and were lined by polygonal, flat or hobnailed cells. The tumor cells gave an epithelial appearance with obvious atypia, abundant vacuole-like cytoplasm and apparent nucleoli. Mitotic figres were easily seen. The stroma of tumor was loose, with basophilic mucinous matrix, diffuse necrosis and hemorrhage in some regions. Immunohistochemically, most tumor cells were strongly positive for panCK, CK5/6, Vim, CK14,epithelial membrane antigen （EMA） ,P63,and P53, hut negative for CD31, CD34, F8, and Fli-1. Electron microscopy revealed a small quantity of tonofibrils and typical desmosomal structures in the cytoplasm of tumor cells. Conclusions Primary PASCC is a rare subtype of squamous cell carcinoma, and should be differentiated from angiosarcoma, epithelioid sarcoma, and so on.